A great place for Franklin Engine info is the Franklin Yahoo group. Go to:
http://groups.yahoo.com/group/franklinengines
Following is a list of the resources I have. Some may be out of date, so you'll just have to check. I have put comments as to what I know.
Franklin Tools – Frank Bailey 1(310) 835-2836 Tools for the engine.
Franklin Parts and Service
Susan Prall Franklin Engine Service 1(903)626-5115 One of the best sources of parts.
Greg Lucas 1(405) 268-3925 Greg is in our group, and could best respond. He is highly regarded in the Stinson community and has been a world of help for me.
Bruce Kown Classic Aire Inc. 1(770)548-2238 He has worked with Greg, advertises in Barnstormers and I have only seen positive things about him.
Jerry DeBallista Deb's A/C 1(903)626-6787 Jerry has worked on Franklins for hundreds of years. He went to work for/with Susan Prall but I guess he is back on his own again. He use to be in OR and has overhauled cylinders for me. They didn't last long. He was VERY slow getting things out.
Phil Davis 1(615)477-5136 I really don't know much about him, though Susan Prall recommends him for overhauls and maint.
Lee Field 1(203)748-7303
Gene Hamilton 1(360)837-1321 Gene is at the point where he really wants to retire. He does great work, OH'ed my engine 18 yrs ago, and has topped some jugs in between. Great guy to work with, but doubt he wants to take on too much more. He is advertising his place/shop/inventory in Barnstormers.
Rick Hoffman Carl Baker Co. 1(541)504-5588 Carl Baker has been selling Franklin parts for hundreds and hundreds of years...ok, so maybe i exaggerate a little. Not sure if Rick is still doing business, but MOST certainly worth a phone call.
Tom LeGrand Nation Aviation 1(866)867-2295
Li'l Red Arrow 1(308)234-1635 A long time Franklin engine place. Haven't really done business with them, but again, worth a call.
Charlie Sullivan 1(815)722-6330
Those that I didn't comment on are not meant as any reflection on their work, I just haven't had any significant contact with them.
Hope this helps.
Larry