Dear Chris,
It's a pleasure to can discuss with you about your HMS Vanguard. For me is the best wooden model I've ever seen in my short experience!
I agree with your idea about the choose for what ships it's good to make a kit. In fact, despite I'm a great fan of Horatio Nelson, I think can be more interesting have a model of Collingwood's Royal Sovereign, instead of HMS Victory.
To answer your question if can be interesting have a model of a War Roman Galley, I think it can be wonderful if it's very detailed and in great scale. As Vespucci said, with a model in great scale, we can chose the perfect figures to use to complete the kit.
I'm not as the other members of the forum, in fact I prefer more sailing ships (about 1700-1800 period) instead of WWII ones, but is only my opinion and, however, an Amati model of RN Roma can be a lot attractive for many modellers in which can be I.
P.S.:I apologize with you for my English, but I can assure you I'm trying to improve it.
Thanks for your interesting posts about the realization of HMS Vanguard kit and my congratulations for your great work!
Alessio