Captain Aktion wrote:I think that's probably the correct answer. However, I like that the door is open for interpretation.
I've pretty much always read it this way: The events of FCTW happened. Sanda grew from some left-over bit of Franky (maybe the severed hand?), was raised briefly in captivity as we see in the flashback (I guess they did still have the hand, right?) and was referred to as Frankenstein by this new team of scientists. Eventually, Sanda gets free and disappears, but along the way manages to leave a bit of himself somewhere in the sea which will eventually grow into Gaira.
Once Gaira shows up and Sanda returns to the scene, they realize that neither is really Frankenstein anymore, and as such begin referring to them as different creatures altogether.
If you like continuity, this seems to be the smoothest way to reconcile it all. Frankly, all it would take is one line, "Well, I guess neither of them is really Frankenstein anymore. Now they're some kind of...Gargantuas."
I always subscribed to this theory as well, and would make sense that they would call the creature Frankenstein up to that point as they knew it was a offshoot.
Continuity is very loose in the Showa series anyway, when it is there, but my mind always linked the two films in this way.
If it bites... don't mess with it!