Sover Wong worked on an F2 I bought several years ago. He's very thorough and in my opinion, well worth what he charged. He is honest and competent. I would have no hesitation in recommending him. I am very happy with the F2 and he told me it looks good as new. He was able to fix a couple of small issues and even upgraded the aperture sensing "ring resistor" which failed (through no fault of his own, I suspect) at no additional cost.