Dan Wright (Modwright) is the only one I’d trust to do any kind of mods, by far. I have a good friend with some of the Kern mods on an SCD-1. No thanks, not for me.
In the last several years, and particularly with the passing of Oppo, Dan’s modding business has taken a back seat to his own excellent component line. BUT he’s currently evaluating getting back into mods with the Schiit Yggdrasil. He won’t release it unless it’s really good, and a good value. Having owned Yggy and a couple other Schiit components - yeah it's a nice DAC, but it could probably benefit from a much sweeter sounding output stage. You can keep up with Dan on Facebook.
Not sure if he’d do a 1-off mod on a CD player - can’t hurt to ask :)