Thanks for the link. I'll check it out.
Keoke, I suspected that was the case. I've done similar repairs to some older Japanese cars where I un-crimped the rolled steel cap to remove the petrified and cracked diaphragm. I've used two-part silicone, wax molds, and pantyhose material to cast new diaphragms too... but I'd like to find a more friendly method of making such parts and performing these repairs.