Thanks for the help so far everyone!
I bought the thing yesterday ( like I said, I have a problem )
It looks to be a Sargent VBM 414, type 3 - 1910 - 1918 with the problems noted in my original post. No body casting lettering / numbering at all, but that looks correct as far as I can tell. The broken frog, while it gives me the willies, looks solid and if I remove the bits, can probably lap it to flat as it is real close now. Regardless, I will look for a replacement ( it is the ' horseshoe ' style that cannot be adjusted from the back ).
The rosewood is very nice, japanning has a few chips, but the rust is minimal, which is a bonus.
The interesting thing is the blade measures out at about .107'' - an old Stanley I grabbed is .085'' - considerably thicker which should be nice. also, it looks like the last person to use it read Kees and Wilbur's article on setting the chipbreaker - maybe just a fluke, but overall, a 100 year old survivor that seems to have been kept together and reasonably looked after.
Like I said, you very seldom see Sargent stuff out here on the Left Coast, so it is a bit of a treat.
Will try to post a couple pics later today - too many projects, so little time - - -
Dave B