I guess your original 1972 liner is still there. There shouldn't be any need to do anything. If it's been regularly tested for gas, then it should be fine for solid fuel again.
For 1972, it's quite possibly only a 7"(175mm) diameter clay flue. In which case, it was probably only intended for use with a standard fireback and a small coal grate. Well worth checking the diameter though. It may be bigger, so you could have a larger grate, more suitable for logs if you want to use them.
If only a 7" flue, then you would possible be better off having a woodburner, or some other enclosed fire fitted. Much more efficient without too much heat disappearing up the chimney. A w/burner projecting into the room looks good too.