Shoot it!! Rifles were made to be shot. I doubt that you would ever put enough rounds through it to change it's value.
While ammunition that approximates M2 Ball would be most "correct", any commercial 30-06 load would be fine. My personal opinion is that for normal range use 15 gr is the choice, there is nothing wrong with 180 gr. 180 gr. softpoint handloads are my Elk loads for my Remington '03 (just before the 03-A3) that I fitted with a new surplus barrel and an Eotech red dot sight.