I am raised with using millimeters, so I had to convert 0.065" so get an idea of how thick that was (1.651 mm). So, armed with my micrometer I went out to the bench and had a look. The leftover groundglass is 2.35 mm, but the glass I had from some abandoned picture frame is 1.85 mm (0.072 inch), so I don't think you should give up just yet on finding some glass.

BTW, I am not really into Hasselblad stuff, but am I right in that is two parts - one plastic fresnel and one ground glass part? For what model? Maybe I can source it over here.