The guide on CMS is very good and their service is excellent. You might pay more for some rare NLA parts.
https://www.cmsnl.com/honda-nsr250r2-1988-j-japan_model49608/partslist/0176.html#results
Stephen did say there was no real need to replace them, but I had my swinging arm re-anodised. Any bearings and seals can be ordered from the codes on each item from any good bearing supplier. I only ordered the ones that were NLA and all went back together with no issues. One of the seals that I ordered from David Silvers looked like a non-Honda substitute
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