Hi Alex, you're not the only one... I've got a 7,5 and a 15 degree one as well but no level one. They seem to be quite rare... Here on my 10TT36 brass carb which will end up on the Ulster head after changing the flange.
Yes they are quit rare, I have several of these floatbowls but non of them is a 0 degree. There is someone in France who I met some years ago which is making these floatbowls but they cost over a 1000,- Euro which is to much for me. Isn't it an idea to see if it is worth to make a small batch of these ourselves ?? Take a look at this website, this guy is really an artist : http://www.brufnut.de Maybe you know this guy allready.
Hmm, those repros have a different (older) form than the 30's TT bowls. The ones I have are "square" not round on the bottom (looking from the side). Still the price is higher than I paid for one complete TT carb with the 15 deg. double float on it... (CHF 850 = £350 or €500). Looks great, nice work but currently I can't and won't shell out that much for double floats.
Wilfried or "brufnut" is a wizard. He can do most things I wouldn't even dare to think about... He rebuild a Binks carb for me in exchange for some brass float bowls. Excellent!