Tuning info wanted

[David Duvall]

Greetings.
I just bought a 1984 Ericson 28+ , judging from the condition of the rest of the boat, I dought that the mast is in proper tune. I am hoping that someone has ,or can point me in the direction of instructions for proper tune. like rake,prebend ,shroud tention.
She's fractional rigged with only two aft lower stays, well it has upper shrouds as well.
and the spreaders are stright .
Thanks you.
David.