Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
According to the parts diagram and the manual there are 37 ball bearings, 19 in the top and 18 in the bottom, they are called #8 ball bearings which according to the web means 1/4".Like these.https://simplybearings.co.uk/shop/product_info.php?products_id=38916&vat_inc=true&gclid=Cj0KCQiA34OBBhCcARIsAG32uvPGEh1MrUYLnvlT3sG_BtrNgFn62NT0DsiaJaeC6kmnygPfawxXsMwaAi_OEALw_wcB£4.33 for 50.
Please forgive me if I've missed something obvious, but if you've gone to all the trouble of dismantling the front end, surely it's a lot less hassle just to replace the whole lot with a set of taper roller bearings. From the way I've read it, it gives the ipression that you are leaving the old races in place and just renewing the balls?
I have seen these advertised may be a solutionhttps://www.ebay.co.uk/itm/AFTERMARKET-HEAD-BEARINGS-CUP-AND-CONE-SET-HONDA-CB500-CB-500-K-71-74-NEW/274677015189?fits=UKM_Make%3AHonda%7CUKM_StreetName%3AFour&hash=item3ff406a295:g:JyYAAOSw8j1dY654