Thankfully on my Olympic they ground on the upper to make it fit. That being said I still had to use a punch to take it Loose every time. And then the rear takedown pin was very loose. . M60 Joe was able to fix it. . A lot of the Radiuses on the Olympics aren't quite right. . So what you've got is basically a one-trick pony. that upper works, but I doubt others will work as easily as that one. It cost me about $1,200 to get mine fixed between M60 Joe and US Anodizing. But I can now say that my gun has been brought truly in spec. And certainly has a higher resale value because of it. . Basically cry once and be done with it.
M60 Joe closed up shop, but I bet Victor at us Anodizing will either be able to fix it himself or send you in the right direction. Good luck.