man... I'd say its worth whatever its worth to you, but wait... what shape is the machine in and mixdown into what ? Good questions to ask.

I hear Remy coming :cool:...

Is it for you or are you the service? I love your username!

You can also try running that 1" tape on a 1" 16track machine. There's probably more of them available and the tracks line up pretty well.
In any event, you shouldn't be looking to mixdown just yet. Assuming that the tape is still in playable condition, your task is probably to transfer the tape to some digital format to preserve the tape as much as possible.
Unless the tape has been preserved in a climate controlled facility made for such tasks, (or if you're very lucky) repeatedly playing that tape as in a mixdown session can yield a significant permanent loss of the high end. It also affects the speed of the machine over several minutes, Not to mention constantly cleaning the heads of the machine.
Tapes from that time period are of 2 types. The older formulation plays better, but the tapes are brittle and can crumble like old parchment paper. The newer formulation won't break as easily, but the oxide mixed with any mold that's developed over the years will , best case, shed with each pass of the tape, or worse case, turns to goo and will gum up the heads of the machine.
I did a lot of these types of transfers. In severe cases I developed a technique that constantly dripped alcohol to the tape path in an attempt to keep the heads clean enough for a few minutes to get a decent transfer. Even then, a 5 or 6 minute song would have to be transfered in sections and then edited together back in the DAW.
Once you get that far, then you can start thinking about mixing.
hope this helps.

Sorry, I've been away. Thanks for all the suggestions and info. I'm the one who has the tape, and I finally found someone with the equipment and skills to do this, who lives close to me. The person I found is well known / regarded and uses analog stuff most exclusively.