there's a guy in Dublin selling new combos based on the 5F2-A, but with a diff rectifier, for about $300
http://cgi.ebay.co.uk/Classic-5-hand-wired-5-watt-princeton-5F2-A-Guitar-amp-/320612068813?pt=UK_MusicalInstr_Amplifiers_RL&hash=item4aa5f7edcd
am I looking a gift horse in the mouth here?
Will it sound poor compared to a Ceriatone 12w model?

ahh so the older one 6v6 princetons are like a weaker deluxe? probably no point for me, since I have deluxe covered. A good price though eh?

I have two 5E3 clones/derivatives (tweedy and modernised tweedy) and a Twin II (ultra clean power), so it sounds like a 12w-15w princeton may fit in the middle nicely
I tried a 70s Princeton recently, and it sounded good. Like a less clean, less powerful twin. I wasn't sure f the tweed Princeton was cleaner than the deluxe.
Do all the tweed amps sound similar then?

I wonder would a diff classic fender fit into the gap in my fendery amps better? I really haven't seen the bandmaster, pros, etc around much in England
Something between 12 and 50w, clean but warmer than a twin. Perhaps I should use my BM50 for that
I had a red knob champ 12 once. That sounded very mediocre, I had it modded but even then it wasn't a keeper

I like your analogy with biology