You could probably fake the four major size groups with a 32 or 38 frigate, a 44 to 50 two-decker, a 64 and a 74 SOL. Just need to sand down and fill...
Based on these charts, I would be comfortable with one large sculpt covering everything from Earl Talbot up. The question then becomes where we split...
1502 BM isn't consistent with something smaller than a 42 gun establishment ship though... but is consistent with something of the general form of a...
Im very happy that you did. I don't have any photos but I know they ran a few games at a con in Australia a couple of years back so I'll see if there...