Hi Folks,
Thanks for your input.
I have split the halve coupling, gearbox to shaft, bolts were very tight and access is not brilliant. The mis alignment is about 9 thou, that is a 9 thou feeler will fit in the top whilst the bottom edge is touching. I have taken the sizes of the nuts on the engine mounts and will be looking to obtain appropriate ring and open enders. The adjusting nuts under the engine mounts are quite large 36mm. There is not enough room for a full length spanner so I will be looking for one that I can shorten. If I take the weight off the mount with a scissor jack I should be able to move the large nut whilst holding the stud by the flats that are machined into the top of it. That is the plan for when I am next at the boat. By then, the wounds inflicted on my arms by various clips and other sharp objects will have healed.