I'll try.

I'll even try to get to a couple of guns
- one mine, a few belong to others.

I can draw how I like it, I can't determine the
type or cut of the diamond (? facets if I recall ?)
as I'm not a jeweller but they would know which type
of cut and what facets to have to refract the light
where we want it from any angle.

Give me a few days.