Bah!!! enjoy what you have ,ride it where you can, if it don't comply with now LONG standing regulations, suggestions
(1) Don't enter or ride it in that class in the race competition environment.
(2) Sell it ,or give it away and find something to ride that meets the class requirements.
(3) Put together a very intellectual and comprehensive case for changes to for-mentioned LONG standing regulations and forward it to relevant Authorities. (To be subsequently ignored re Politics!)
(4) Leave this sport and pastime as many other pissed off individuals have done,,, only to find more f**k**g Rules and Politics in their new chosen form of recreation.
1975 was 37 yep 37 years ago......
Cheers Tim754