I got a case some days ago from Yuki, I guess from his new source. It is the worsest case I've ever seen in my rep time! Everything is wrong, like lug shape (there is missing a lot of material!), lughole position (some higher some lower), rehaut too shallow, crownguards way too thick - and the two biggest things are, the tube is not centred between the CG's and there are between the lugs only 19,2 mm!? That means you can not put a endlink between the lugs without shaving it down, or the lugs (that's what I did)!
So if you don't have the tools and skills to correct these things, stay better away from Yuki!!!
BTW, there was never a 1680 case from MBK! Thery are all 5513 engraved, also the rehaut and inner case dimensions are made to fit a 5513 dial. I tried often to put a gen 1680 dial in these cases, but the dial diameter is too big. Only a correction on a lathe will make it 1680 like. On my next project I will use a MBK 1680 case, which will be machined to take a gen 1570. After that it goes straight to Phong, he should regrave the case to 1680. I think this will be the best looking 1680...
Also don't underrate the cartel subs! They are also very good. Only the short CG's sucks...