Looks like a standard lipped roller bearing to me. But more bemusing is the timing side main which looks like an end fed crank conversion, (reckon I can make out some rollers) but with what appears to be a bronze outer track....I would have expected all steel. Cam bush looks a bit thinner on the face...is the cam gear kissing the crankcase?
Choice of type and brand of drive side main bearing is more wide these days, plenty on the forum featuring bearings which demount easier than the original type. If it is an end fed conversion, does the timing side bearing now eliminate crank float? I'm sure earlier incarnations used a bearing which combined axial and radial limits.
As stated, maybe this glitter was part of the initial bedding in process. Cleaning out the tank, watching and checking could have saved a lot of work.
Looks like Col has also had the same thought about the timing side...not what it first appears?
Swarfy