I agree with the others- those old joints are fine as long as they were done correctly ( twisted before soldered).
If you decide to remove the old tape to inspect those joints, I would go back with a few layers 33+ half lapped sticky side out-starting about an inch or so beneath the bottom of the joint and ending in about a 1/2" excess past the top,( any excess is folded over) and then top that off with a couple of half lapped layers 33 sticky side down or better yet, temflex 1755 (the old fashioned and very sticky type of friction tape)- done that way, and I guarantee those things will be adequately insulated and will still that way almost forever. Of course if you don't want to tape 'em, there is always heat shrink.
It's always funny when folks will get worked up over a taped joint, but they don't know (or forget) that years back that was really the
only way to insulate them- the trade has been an evolution. I could see though where some would have an issue due to ease of inspection- you can't see thru tape.