Chris what size is the plane, the small 30 size or the larger 60 size? If its the larger you can get a fiberglass cowl from Fiberglass Specialties.
http://www.fiberglassspecialtiesinc.com/ The big Chipmunk is listed as a 40 size but its really a 60 size plane. I have one of their cowls for my 65 inch Super Chipmunk which is the "Forty" size but mine is getting a new OS 91 Surpass II and my plane is New in the box with the original Supra folding retracts that are no longer made also new in the box. The plane is mint and my EZ pride and joy I cant wait to fly it. I had the 30 size with an OS 48 Surpass that I flew so much I wore the plane out and the 48 needed to be rebuilt I dont know how many gallons I flew through it but I flew it for 6 years[:-]
I hope that helps and good luck.
PS: is the plane new or used.
Viper