I recommend dumping them immediately to digital and working from there. Depending on the condition of the tapes, you might get 0 plays or 100 plays from them depending on the type and age of the tape (do they have sticky shed issues?). Are there any splices? I can tell you from experience that 30-50 yr old splicing tape is going to fail (I redid about a half dozen of them last year while recovering some old tapes)
Why would you want to add "saturation" to a one mic mono tape? All you are doing is distorting the original sound. Most people want to recover as much of what is there as possible. You already have all you "tape mojo" on the tape (whatever that happens to mean. I have yet to see a "% Mojo" spec on any tape deck) At least if you have a good capture of the original tape, you can abuse it however you want. Dump it to a new tape at +10db so you get lots THD ... er sorry, saturation. Run it through a tube pre for more saturation, dump more eq on it to bring out the hiss, and add more wow and flutter.
I don't know how much you have to "remix" but have you priced tape lately? 10.5" x1/4" reels are about $75-100 a pop. The half inch tapes for your 80-8 are about $100 to $150 per reel (do you need it on a reel or just pancakes?) You get a whopping 30 minutes of recording time with a 2500 ft reel..
I bring all this up because you have asked a lot of very basic questions, things that anyone with experience would know. I wonder if you really understand what the consequences of going "all analog" really are. Before you sink 3 or 4 thousand $$$ into buying equipment that needs to be maintained (calibrated, cleaned and aligned) you need to understand where you are going. You wouldn't recommend that a first time guitar student sink $20,000 buying a vintage Strat and another $5000 buying a vintage SuperLead, would you?