Spotted on Ebay, not sure if it's what it's being called - RD350 aluminum swinger?
https://www.ebay.com/itm/363548788402?hash=item54a53246b2:g:8SwAAOSwJoVhR16g (https://www.ebay.com/itm/363548788402?hash=item54a53246b2:g:8SwAAOSwJoVhR16g)
(https://i.ibb.co/hRZ6H1X/52-FA2-CD2-0-D17-456-F-8-BC4-7-AC1936-AA28-A.jpg)
its to be avoided.
https://www.2strokeworld.net/forum/index.php?topic=3741.0