Dan: Nope don't want to switch jobs. I find that my hobbies lose their appeal quickly when I do them for someone else. I deal with software all day, and it's a great switch to work with my hands on physical stuff. We build the software that controls unmanned fighter jets for the DoD . . .
JFP: Yup, you're right. I definitely don't want to buy this tooling. My operations guy happens to own a bunch of machine tools and offered to make something like the Cheetah tool:
http://www.cheetahonline.com/technical-articles/rms-seal-replacement-on-m-96-porsche-engine/
Gonna try that, since it looks like a pretty elegant solution. Not sure how I'd get the seal precisely set at Dan's 13mm depth with just the PVC coupling as a driver . . .