Well I got some encoders and cable for x-mass .. so let the fun begin
I was kindly given an encoder ready bolt .. which I had some doubts about being able to fit to my existing ground board as the bush needed to be removed (glued in there)and drilled out for the larger bolt.Thankfully I smacked it out without much damage and was able to flip it to get a nice snug fit again..the torn ply underneath will be hidden by the locking plate..which I had to make another of as the overall thickness of the rocker box /ground board stopped the bolt locking down by about 5 mm.
The pole for the ago navis is 32 mm I'm planning to run the cable down the inside of the tube atm.
a few pics and a birds eye view of proceedings so far