If it were me, I'd change the fluids and take a crap shoot as to whether it was going to cause weeping out of the seals.
As mentioned, I would replace with what came out. Basic 80-90 weight for the raera axle and ATF for the trani. I would not go with Synthetis anything. That seems to be the curse for leaks after a car has had Dino fluids for years and years.
For replacing the fluids, make sure you have a Siphon tool , they look like a grease gun and cost about $10. you will need it to fill both teh Trani and the rear end.

As mentioned...make sure you can get the Fill Plugs off before draining the fluids. It's always nice to be able to put fluid back into the car : ).

I have always replaced all fluids when I buy a used car. I change Trani and rear axle fluids every 100K miles.
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.no.net/ebrox/Tony's%20cars.htm