I did contact Fiberglass Specialties, they said since the Yak is an ARF they hardy doubted they would have it,  THe guy I bought all of his stuff/junk. I think he bought on obsession. Out of 13 planes and 4 helicopters you can tell especially with the helicopter he was buying and learning how to fly with each model. So some things have been crashed.  So I hardly doubt he remembers hardly anything. 

This particular plane  the cowl is semi oval. I thought about sketching the cowl shape with some pics and see if Fiberglass Specialties could make.

During my endless persuit I did find a few people with a 50cc plane. I am hoping I can give them a buzz on Monday.

Please correct if I am wrong. I measured on the aileron side of the wing. and I came up with 361/4 then I read through the fuselage and I came up with 75/8".  So I called it 80". I am not taking in the account of curve of the wings and the wings not being on the plane. Therefore I was looking at YAK 54 with 80-81" wing span with 50cc motors.

thanks for all of the help.