There are businesses that specialize in this sort of thing, the whole gamut from recovering the info on old tapes to reading old formats of computer disks, etc. I can't remember exactly where I've seen them, maybe in the small ads in the back of trade papers such as TV Technology.
It would probably cost a bit, but it would be cool to get it onto a CD. One good playback could get it into a digital format that would last a good long time.
Anyway, don't delay. The tape does age badly.
You don't say how the tape is "suffering from age". If it seems stable enough to risk it, fast forwarding & rewinding it will help to keep it unstuck from itself.
Incidentally, in my experience sometimes those old recorders had good recording circuitry, but poor playback amps, so when you play the tape in a good machine the quality can be surprising.