Been there, done that. The only solution I could come up with, was finding one in a junk yard. It is a very easy fix. Mine broke simply because the plastic got brittle. Not likely a result of the mechanic doing anything untoward. You can use it without the ring, but it is also what holds up the boot. If you head to a junkyard, be sure you have the right tool. There is a small spread pin that passes thru the stick sift shaft and the plastic ring -- you simply push the pin thru. Good luck!
I came here to write a post about a no-start but I think I can help. I have a stock shifter with boot for a 1998 MTX out of a SVT. If it will fit your application I will send it your direction if you pay shipping from Sacramento, CA.