My brother-in-law Brian Teather has the old boiler-plate rudder from Mañana under his garden shed in Sheringham. He might be able to weigh it for you (he's at
brianandjanet@btinternet.com ) He replaced it with a Parker 21 rudder at my suggestion and was delighted with the effect it had on the balance and ease of raising. He is now a Shrimper so we don't see him on here any more!
Geoff (ex Sinbad Zalophus and P21 Cygnus)