With the engine out of the frame and, to be honest, after discovering so many other things worng it makes sense to do a strip and rebuild, rather than 'bung' it back in and hope for the best! However, I don't think there'll be too many problems as it seemed to run OK before I started on the restoration. I know the old adage: 'if it ain't broke, don't fix it' but I just want to make sure.... so I'll keep you informed.
I already have a gasket set and all the necessary oil seals, gunk and hand cleaner, so, in the next few days, it's time to get my hands dirty, I guess!