Pratt & Whitney J57-P-55 turbojet Needed

Looking for a source for the P&W J57-P-55 exhausts that powered the F-101 Voodoo. 1:48 scale, to fit the Revell/Monogram kit. I tried Scalemates but nit much found there. The kit pieces were off-set halves and the sanding required to eliminate the joints removed all of the scant detail of the molded pieces.