If you really want to persevere with this project, do run trials
first with glass and pmc.
Go to a mall and buy some similar rings, there only a dollar or 2,
experiment with them FIRST before you waste too much time on what to
many of us professionals here consider to be a waste of time. As a
professional you must make it clear to the customer you either do the
job on a fixed price basis, and your sure you have done your sums
correctly, or you charge by so much per hour like a profesional
person ie, lawyer accountant, doctor etc and the Professional crafts
person, ie carpenter, plumber etc.
Otherwise your really running a charity with no income. Have fun.
Apologies for the double post, computer glitch, and a bit of anno