I'm glad you had a good experience. Garry's is capable of doing good CLA type work, with emphasis on the C, maybe even the L, and not sure about the A. You sent him an electronic camera and he cleaned it up. That's far different from repair and adjustment.
I sent him an OM body a while back, he returned it clean, but "fixed" a problem with the mirror lockup by gluing a piece of covering over the hole so it can no longer be seen or accessed. I knew he likely couldn't fix it, so I gave him a pass. I also reported another issue (the hot shoe only works with high voltage flashes) and that was beyond his ken. He didn't seem to even understand the problem, reported it working fine.