Though i would start a new thread on this as the results have been fantastic, also it might not get picked up on the other thread. I would image this could be done on other Vauxhall models but for now just focused on the HB.
So having considered my options for the worn hinges on my HB i bought a 7.5mm reamer as after measuring the hinge pin and the worn mount decided this would be the best starting size.
I started on the body mounts, lubed up the reamer and slowly worked it through, very easy with only a minimal cut it would appear, it was easy to start off as the reamer has a very slight taper.
Bought this branded quality reamer off line for a little over a tenner.
Not a great deal of room so used a 6mm spanner to turn it.
No problem, the difference with the reamer is you are left with an exact cut to the reamer, ie 7.5mm if you used a drill you would end up with a different size.