Hi Edd, you should be able to sort it from these pics (original 1978 assembly plans for my Optimist- see my harbour,- might pick up the stays from that) which I'm re building. If you want me to PM you, -PM me with email and I can send them to you that way as well (will probably come out larger/ be able to zoom in a bit maybe)

Original had a Graupner winch, but you could substitute a sail servo using the same sheet layout. Sheet tensioner hooked on 'P' is a rubber band. I have replaced the original stays with .020 stainless wire fishing trace (original wound trace rusted and frayed) which will last forever and no holes in fingers.
JB

She looks a very nice boat, I have found a couple of Youtube offerings of her sailing, you probably have too, but that doesn't really help. My guess would be that the steering servo would be under the stern deck, between the rudder and the cockpit. The sheet servo will be under the cabin top. Hope that helps.

Cheers, Nerys