I don't know about any monetery value but have you considered donating them to The Imperial War Museum in London? They preserve them, give you a transcript & they're stored for future generations.
Plans for blockships to erm block the Kiel Canal I think
The last elective VC was awarded. A 19 y o Lieut called Victor Crutchley won the election (OK boys, there is one VC to go to you lot - you decide who is to get it. Crutchley won)
So there will be some interest in these papers
Why not write to the IWM first ?
And then try an auction house - Dominic WInter see the internet may well take them on.