Finally out ! Freakin bolt fought me every step of the way.
As the bolt was hollow it was straight forward drilling down the centre.
l tried as l drilled to knock it out thinking with just a thin part of the bolt left it might come out. No
Once l drilled all the way through l used a ground down a hack saw blade to cut through the length of the bolt and free it up but even then it took a fair bit of effort and lube to get what was left out
Took weeks to get this out but other than some minor damage to the spacers from the angle grinder, we all came out of it unscathed, bolt excluded.
Cheers
Geoff