I have the adapter that Sheldon sells and this old Continental had the one piece crank with the old cone and bearing set up the inside of the BB housing on the frame is machined. .515" deep and the adapter rings are like .587 ( I converted the measurments to decimals for my ease of thinking) so what I have to do is take some of the thickness off the back side of the adapters so they will seat against the outside of the BB housing on the frame. I'm really fussy on fits and gaps and stuff like that when I know it should seat so its no problem 5 minutes on the old Leblond should have it fixed in a jiffy. Then I can get a new sealed BB and it will be skookum