So had the starter serviced and checked this morning.
Everything seems fine, nothing was damaged and since I cleaned it out, he could check all the connections etc.
It all looks good, nothing too worn and he activated the motor and it spun with no issues.
So need to double check the battery for voltage, even though it seems ok.
I think it could be a wiring issue now or an earthing problem.
Going to get out the Fluke multimeter tomorrow and start to fault check stuff, hopefully its an easy fix or a grounding issue.
I do worry about the electrical smoke that came off that area, so need to check that out too!
Fingers crossed its not a major issue!