I will reiterate the fact that any 42 build is difficult and expensive, also what Kime said in the cheaper you go the harder it is !
my latest build was a pt case with rehaut taken back on the Lathe, I redrilled the crappy positioned lug holes and laser welded the case for better accuracy. Sure this isn't easily accessible for most, but I didn't want to spend $1k on a average caseset either tbh the pt case is ok and fits ETA well or clone np.
i used a phong bezel assembly and a gen 116 plexi but a Tonnywatches insert all with minor fitment issues.
Gen crown and tube fit with no retap also.
i also did a build with a cartel gmt case and shaved off the cg's which worked out well and also fit plexi and bezel no problems... plus the gmt movement is ready to go !