Finally! After waiting two months for the local shop to get the H/W converter, I ordered one from Cathy Church. First one had a bad o-ring groove and wouldn't seal. Second one did the trick. Just put it together on the SP-350. I tried a few quick test shots in the kitchen. F2.8@1/25 and F8@1/1000 against a white background in good light and a dark background in a dark corner. All pictures came out perfectly exposed. I'll play with it some more this week and take it to Monterey this weekend. Pictures to follow.