Could someone tell me where to find - or tell me - the fork ear part numbers that will fit a 1968 CL450K1? Per Bike Bandit I see a left fork ear is 5165-292-670Z, the right is 51602-292-670Z. However I see other CL450 fork ears on Ebay that look like they might fit but with different part numbers. I'm wondering if any of them would fit.
I looked for some NOS fork ears for my own 68 CL, to answer your question, yes, they'll all fit with some manner of looseness. They also won't look the same. The other, later, numbers you've noted all have a hole for a reflector the early ones don't have and when the spring went from external to internal, the upper part of the tube changed to a full diameter, from a reduced diameter. Spacing will be similar and I guess you could find a grommet to fill the gap.
I'd hold out for the correct, unmolested, part numbers.