Another thing you might try..
Is to check on availability of "generic" bearings/inserts. Most of the major bearing manufacturers catalog bearings according to their specs..besides the actual engines they correspond to.
What you do is mike (using a micrometer and/or vernier caliper) the dimensions..then check with a bearing supplier to see if they have anything that matches those dimensions. Or have them mike them for you.
I haven't done that on Honda's..but found bearings for other older bikes..and auto engines that way.
I'd also do an internet search (may take some time) of all the older Honda dealerships..that have been in business since your bike was built..see if any by chance have old bearing sets tucked away in their parts department. Main bearing sets don't take up much room.
Hope you find what you need. Keep us posted on your results,
Ichi
