Rear Axles and DIFF Question

[V8chpr]

Hello, everyone. I have a 72 C10. I put it on the lift today and started out replacing the rear drum brakes. While I was into it, I decided to pull the axles and replace the bearings and seals. I have owned the truck for about 20 years, and I am the third owner. I am estimating that I have put 30K on it in the time I've owned it. It has a little over 124K on the odometer.

After pulling the axles, I pulled the diff out, thinking I was going to put a posi back in. Now I am having second thoughts. I guess my question would be, if everything is working fine, should I just put everything back together with new axle bearings and seals OR go ahead and replace the diff with the posi and a new ring and pinion to have a new rear end? There was a good bit of play (backlash?) on the axles to the spider gears. The backlash on the ring and pinion did not seem excessive by feel. I have attached a couple of pics of the splines on the axles. There is obvious wear, but I don't know if it is worthy of new axles. I would certainly put new axles back in if I were to put a new diff in. The ring gear and spiders do not show any obvious wear signs although I know they have it. As far as I know, it is the original rear end.

I hope I haven't rambled too much and have made sense. Thanks for the input.

Chris