According to the info I have the shorter, 24mm, 10mm bolts are all of /5. The longer ones,32mm, 10mm are until Sept. 1975. If the longer ones fit you can use them but I wouldn't try to drill and tap to do that. I think some of the later /5es might take them but not sure at all.
I have a really old puller that I use for the flywheel. I think some with out a puller are stuck with kinda rockin' it off. Take your time. Don't force it.