There's a lot of credit to spread around for this one. Pablo Raw pointed out the key "J" similarity in the blades in a comment on this post from earlier today. I only know Pablo from interactions online, but I will buy him a beer (or whatever he wants to drink unless it's on this page) if we ever meet. (Update 1/19/2016: it turns out Cleo pointed the similarities between the blades of the Nova Scotia and Italian eBay swords a couple of days earlier in the comments in this post). Peter Guezen's sword comparison showing the blades made it much easier to spot the similarities. Killbuck pointed out similarities in addition to the "J" and made the illustrations for this post. None of this would have been possible without all the people who found these swords and made them known to us. Good job, internet. That's a win for the good guys.
Now on to the observations.
The blades of the Nova Scotia (Oak Island), Italian eBay, Florida, and France swords have several distinctive anomalies in common. These anomalies include a linear, J-shaped groove or ridge on the distal portion of the blade (all four swords), a bump or depression near the tip (Nova Scotia and Italian eBay swords), two bumps/depressions along one edge (Nova Scotia and Italian eBay swords), and a linear ridge/groove in the proximal portion of the blade (visible on the Nova Scotia, Italian eBay, and France swords).
And the similarities in the blades amplifies another problem for the "Roman" interpretation of the Nova Scotia sword. What about the California sword? I argued on Saturday that, logically, the California sword is probably the closest to the original Mother Of All Fake Hercules Swords (MOAFHS). It is the most detailed and has functional blade characteristics (fullers) that are absent from all the other swords. If the California sword is closer to the MOAFHS than the "class" of swords united by these blade anomalies, there is zero chance that the Nova Scotia sword could date to ancient Rome.
The most likely explanation, I think, is that the Nova Scotia, Florida, Italian eBay, and France swords are members of a generation of replicas that post-date the California sword but predate the Design Toscano swords that are currently being produced.
If you want to take heroic measures and continue to perform CPR on the "Roman sword" interpretation even after the patient has stopped breathing, you could still attempt to make the argument, I think, that all of these swords were copies of some "original" authentic Roman artifact and that I have incorrectly interpreted the California sword. One could argue that some of the copies (i.e, the Nova Scotia and Florida swords) were made in ancient Roman times while the others (i.e., the Italian eBay and France swords) were copies produced much later from one of those "original" swords. But . . . logically? Really? To say it's an incredible stretch is being kind. The similarities among this group of blades (some of known replicas) reduce the probability that ANY of them is of ancient Roman origin to one that is vanishingly small.
I'm ready to stick my fork in this "Roman sword." I'll be curious to see whatever metallurgical data are out there, if they ever materialize, but I'm almost certain they won't point clearly to a Roman origin. It just doesn't make any sense.
If you decide to join me and stick your fork in the myth of the "Roman sword from Nova Scotia" and declare it done also, you can also stick your fork in the credibility of J. Hutton Pulitzer. In the original article in the Boston Standard (and numerous times since) Pulitzer declared that the sword was a "100 percent confirmed" Roman artifact. No wiggle room. All the marbles. Confirmed. A done deal. If the sword goes down, so does any claim he has to being a person that can competently interpret a piece of evidence in terms of relevance to the human past. Sayonara.
Pulitzer has already said goodbye to his credibility as an honest person, flagrantly lying about key pieces of evidence (for example) related to evaluating his claim that the Nova Scotia sword is a "smoking gun" that proves Romans visited the Americas.
It will be interesting to see what Dr. Myles McCallum has to say about the sword on tomorrow's episode of The Curse of Oak Island. We've been chewing away at this issue for a month now without having the benefit of examining the actual sword firsthand, and this will be our first look at an archaeologist directly handling and evaluating the thing. Even without the benefit of examining the actual sword, we've come up with substantial information and analysis that bears directly on the key question of whether or not it's Roman. Based on what I've seen, I'd say it's almost certainly not. I'm willing to bet that McCallum comes to the same conclusion: not Roman, probably a souvenir produced in the last couple of centuries. I'm really impressed (and proud, honestly) of the how the inquiry has progressed here, and I think it's going to end up being a classic example of how there are multiple ways to get to the same (correct) conclusion. It's something that archaeologists have to be good at. We are never left with material remains that tell the whole story, so we have to figure out ways to ask questions of the evidence that allow us to discriminate between possible explanations. That's science. If science works (and it does), there are multiple ways to arrive at a correct answer. It's comforting when you arrive at the same answer through different means of inquiry. That means it's probably not an accident.
I think the myth of the "Roman sword from Nova Scotia" is more-or-less busted. We were handed the claim without the accompanying analysis that would supposedly prove the claim and were told to accept the interpretations on the word of someone who has demonstrated himself to be less than trustworthy. Even without any access to the original evidence or data that supposedly underlies the claim of a "100 percent confirmed" Roman artifact, we were able to develop our own lines of inquiry that suggest an evidence-based conclusion of "99 percent baloney." I want to dump a cooler of Gatorade over all your heads right now.