Hello to all, I am new to this site but I have always had a SP since highshool 1983. Well I found a decent little 23 Pacemaker sans its GG. The fram has ridges that run around the where the glass sits so no Fresnel. Please wish a fellow SP fan, good chopping when tonight after class I am going to attempt to cut down a bigger piece to fit the 23 hole.

Ground glass cuts like regular glass if:
1). Glass must be clean.
2). use the cutter on the smooth side.

Hello and thankyou to 45PSS. I washed my little ground glass and did the cut. Did it a wee too big and did the last lap literally with lapping on a piece of wet/dry sand paper so now the ground glass fits with just a teeny bit of wiggle.