I took the head from an old VW air cooled in to have them rebuilt. A few thousand miles the roka valve, where it was welded to the stem, broke. The shop said it's too bad, they didn't install the head, so I eat it. Roka was going to give me the cost of one valve, $2.25. The shop soon after went out of business.
Wish I had an old friend who was a country lawyer to take the case.