Welcome to the Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines - Enjoy!
I am aware that if you´re dead set on an original Jensen #15BL, this posting won´t be much good, but if not...Perhaps you could lure Bruce "Saint Paul Steam" to upgrade a standard genny with ball bearings for you.He has done this with great success on several during the years
I've Seen your post from the beginning , I have 3 cast iron based #15 , but no ball bearing #15 aluminum base generators, except for the twin 25/25BB plant that's for sale on EBay right now.