You said you couldn't find Viton o-rings in the right size.
You might try OringsUSA.
I've bought from them for odd sizes before, and they have a wide variety of materials available.
Sorry for possibly enticing you to exceed your $$ limit. wink

Kevin
1951 Chevy 3100 work truck
Follow this saga in Project Journal
Photos
1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car)
Busting rust since the mid-60's
If you're smart enough to take it apart, you darn well better be smart enough to put it back together.