It seems like a real shame to paint over that wood veneer. Stain and polyurethane, or better yet shellac for appropriate steam punk materials, would be my first choice.
OK, here are the nose cone dimensions:
View attachment 400237
The overall diameter and shoulder diameter are per BT-80. The core hole, if you're set up to do it, is for the OD of a BT-5, which I want to add in order to reinforce the waist. Or maybe just make it a half inch and I'll use a dowel. Or leave it to me to figure out how to drill. (Getting my drill press ready to go will be a lot easier than my lathe.)