Does anyone sell a oil filter housing service kit with spring, disc & retainer? I had to remove those bypass items to clean a dirty housing. After 50 years I'd like to refresh the parts if possible.

 

I don’t know if anyone offers service parts for those.

Most people remove the bypass, tap the hole for an Allen head setscrew, and call it done. Granted, if the filter plugs the oil won’t bypass, but if the engine is neglected enough to clog up the filter the bypass will be the least of your problems.