For my later (six bolt) CVs I've always just purchased the joint by itself.
If you used the search feature on this list, you'd have found this:
Me, I've always tried to replace a broken boot with a one size fits all boot from J.C.Whitney (but haven't looked in years). You snip off what you don't need on either end. Zip ties have worked fine for retention, though you could use clamps. But I assume your boots are good, so you'll reuse them?
