Are you north or south of boston?
I'm south of Boston and might be able to get you to a one or two people, or might I be able to help a bit. Best thing you can do would be to get Panics books on Flatheads www.victorylibrary.com.
There are not to many people left in the area that can do compitant work on the old motors. The ones I know can do the standard rebuild work but not much more. Most of the other mods you might have to do for yourself.
Click to go to the Flat Boy Web Site.Flat Boy
Why buy it when you can make it