i can vouch for a handful of the people, zacks, sk grimes, and midstate camera repair all in rhode island and youxin ye, of massachusetts
they have all done top notch work for me without issue at a fair price.

i cannot vouch for mr certo6.
while others have had OK experiences, be aware not everything is wine and roses ...
he did the absolute worst camera fixing i have ever experienced. i will not pollute your thread with the details ... but
i wouldn't buy anything sold by him, or send anything to him to CLA, even if he was the last person around to do it.