i have a fixed keel rl 28 with engine in stern locker
ex charter boat she will get makeover soon just got her
need to buy bottom rudder gudgeon looks cast
The rudder gudgeon is unlikely to be available. The cast fittings, such as the mast tabernacle, were made by Fico who no longer exist, and some were made especially for the RLs.
Your best bet is to find a marine engineer who could make one for you. It is just two pieces of metal welded together and an appropriate hole drilled. I had my mast tabernacle welded when I snapped a piece off and the cost was not unreasonable. Any engineering place could do it but a marine engineer would better understand the forces on the rudder.
Also, I know it is your bottom gudgeon that needs replacing, but it might be worth a look at the gudgeon modification by Steve Illa in the Tips and Modifications section.
https://rlyachts.net/tips-RL28SteveIlla.asp