Thanks folks for the input on where to purchase shims and alternative mounting techniques. I understand that Ernst is no longer in business. As to my current project which is a Pilatus Porter 94" ARF the sanding option is a bit difficult, although I will use it in future kits that I build.

So, I am going to try molding a shim to fit the backplate area of the BGX-1 from epoxy, graphite, and fibres unless someone talks me out of it. I have been advised by others that using washers on larger engines places the mount in jeopardy...so, building a tapered shim is suggested...(per ken laski).

Stewart Tittle