Phil Wood makes excellent French threaded bottom brackets should you need to replace yours.

Not all Puchs and ADs were British threaded. I have an Ultima that is Itailian threaded. I haven't come across a French threaded frame, but I wouldn't count it out. Also, if the drivetrain (fixed) cup unscrews counterclockwise, it is either French or Italian:

http://www.sheldonbrown.com/tooltips/bbcups.html

Your best bet for touchup paint is to mix it yourself. I use model paint and it works fine.