starting relay cut off 5EB 81950 20 Do you have one I can swap with you and test

[Falcon 269]

Not local, so can't help much in practical terms.  However, you could try removing and cleaning both neutral and side stand switches if you haven't already.  Both get really crudded and oiled up but provided the wiring is intact, it's possible to blast the crap out of the switch internals with WD-40.  You can also jump the contacts on the sidestand switch as a get-you-going measure and/or for fault-finding.