Replace with new camshaft,it's almost too easy to overlook during a rebuild. Camshaft bearings are pressed into the block and thus are usually done by a machine shop. You would not rebuild an engine without replacing the rod bearings, so why not the cam bearings? Minis have one of two sizes of cam bearings; 850/998/1100cc blocks use use
AEC3046 which has one bearing smaller in diameter than 1275cc, see
AEC3063 Some late 1275cc automatics also used
AEC3046 bearing set. These have been fitted to other 1275cc blocks in error and without any problem.Usually fitted by a machine/engineering facility.
Spridgets and Minors have the same block as the Mini, therefore these same cam bearings.