Wow, that is news to me. He has done a pile of C93 rebarrels. That seems odd. Did Jeff say why? I'm guessing you'll do a paddle mag release install, plus a refinish? If so, I'd also add an optics rail on the top. You must have been hanging on to that 33K 300 BLK OUT barrel for a while. They have been out of stock forever. What do you plan to use for a locking piece? What are you using for a can? Have you considered 7.62X39 instead? That is the way I went in the AR platform. EBR makes 220 gr subsonic that will cycle the action. The plus side is that I use steel cased Wolf for supersonic ammo at $0.20 per round instead of supersonic BLK OUT at $0.70 per round. Much more cost effective, at least in my book.
Joe at Dakota Tactical http://www.dakotatactical.com/webstore/index.php, Jason at Investment Grade Firearms http://www.investmentgradefirearms.com/, Mike Turner at Turner Fabrication Turner Fabrication, Mike at Michael's Machine (618) 570-8641 is best to call, are the guys that come to mind. There are a bunch of smiths that won't work on clones but all these guys do. There are also some new guys like Moore Advanced Dynamics https://www.madkc.com/ (MAD), TPM Outfitters http://www.tpmoutfitters.net/, Brethren Armament http://www.brethrenarmament.com/. I've had Joe @DT do some work for me, but I don't know about a rebarrel, but what attention to detail. I've also had Jason do some work. Again a great job but just like Joe you might have to wait a while. Good luck with the C93 project.
Scott