UltraCast has an incredible P&W R-2800 engine in 1/32, that turns out to be from Vector.
Apparently UltraCast is a VAR (Value-Added Reseller) for Vector, and as Vector apparently does not have a website of their own, this makes it much easier for modelers to acquire their amazingly detailed castings.
SprueBrothers.com also sells the P&W R-2800 engine.
LindenHillImports.com sells Vector parts, but apparently does not carry the P&W R-2800, although they do carry this highly-detailed P-51B wheel well assembly.
