I'm building a tire carrier for my 80 - this is where I'm having the problem, though I have to say, this kind of thing comes up for me often in other projects as well.
Say I have a set of holes on the existing frame - and I need to put new plate over the holes - I'd like to drill a new set of holes through the new plate in such a way that they align with the existing holes already in place.
So the problem starts when I place the new piece of metal over the existing holes, essentially covering them up - there must be a trick on how to get new holes alined perfectly with the holes behind the piece you're trying to install...
This is assuming you can't get in from the inside and mark the holes from the back - that would be easy....
Hope that makes sense - if not, here is the photo. I'd like to bolt a steel plate between the frame and that protruding arm in the photo and then weld the tube onto the plate:
'95 FZJ80 with Lockers; Home made sliders - and it shows...
285 DuraTracs; Seat covers, CB radio