Which would you rather? Better brakes, better hitch, or better wheels/tires?
If it isn't broken, why fix it?
Axles supposedly only live about 25 years or less, even though we just moved our 75 with original axles 1,400 miles and it towed just fine.
WD hitch, if the nose of your TV goes up when hitched, you'd be better off with one. Again our 1,400 mile tow, normal hitch, the F250 didn't know it was back there other than a drop in fuel mileage.
Disc brakes ... (me personally) why?
16" wheels ... see disc brakes. The original 7.00x15 tires on our 75 made contact with the lead edge of the wheel well, so replacement tires we're smaller.