Depends on the age and the quality of the originals. If the tapes are on cassette, copying them to a digital medium might be a good idea. I found a load of cassettes I'd recorded years ago - just stuff off the radio - and everyone snapped in the playback. The tape had gone brittle.

One of the bands I played in made a CD(R) some years ago - and, when I played my copy recently, it sounded like a bad 78rpm record - the sound was totally gone.

So, keeping a few copies on computer and CD or other medium might be a good thing. As for 'remastering' - i.e. tinkering with the sound quality - that may or may not be necessary and is down to your judgement.