The assembly goes bearing, shim, retaining (snap ring).
Shim is a circular grease retainer for the original open bearing. Shim part no 67-6072, just a thin tin can circular pressing with a slightly raised centre.
Snap ring part no 67 6067. Yes, similar spring steel. Nothing special. Any modern wide internal circlip to the locating groove depth and width will do.
If you use a modern sealed bearing and don't have the shim, then a substitute ring will be needed to bridge the gap between snap ring groove and bearing outer race. Otherwise the bearing will not be positively retained laterally. Easier to see than explain.
Swarfy.
