Thanks to all, again.
Yes, I had heard some techs say not to change fluid on old transmissions, but their reaons were vague, at best.
I have always thought that fresh fluids would never hurt, but wanted to check it out with you all.
I will be changing ALL fluids, including trans, rear end, and brake. I'll leave the old air in the tires, though!
Thanks again for all the replies!