If I understand correctly, the OP’s question is about which production companies are the elite in terms of fit & finish, quality control, and consistency. I’ll fight my compulsion to dig into the way “grail” is used these days, and focus on answering the core question.
As of 2018, this is a list of companies I’d rate as high in QC as Chris Reeve Knives, who were the gold standard for QC for years. The list is in no particular order:
Reate
Koenig
Olamic
I’m stopping it there, because those are the only companies I’m 100% comfortable describing as similarly, consistently vault-like in their construction. You can pick one up, get a feel for it, set it down, pick up a different sample, and feel like you’re holding the first. Everything from the seams to lockbar tension are going to feel the same from one sample to the next. Every design element is executed very well, every time.
If you ever get a chance to go to one of the big shows and handle these back to back to back with other brands, you will really appreciate how well they stand up to competitor construction.