If your planning to sell I would definitely fix the old style bolt release. The new owner will certainly appreciate it and it will help you get top dollar for a very nice rifle. The appearance of a rifle is the first thing a potential buyer sees. Which I am sure you are aware of. Good luck.The serial number info indicates late 60's,early 70's so it's not from Remington's closing. I bought this rifle in the late 70's from a Gunsmith/Benchrest shooter who had a terminal illness.. I have also found on some reputable sites that they didn't mark their early rifles 40 X.
This is a quality rifle that shoots. Ascetics is in the eye of the beholder.
The hole in the pic is from an aftermarket bolt stop that was commo in those days. It broke so I put in a factory bolt stop. I may still have the pieces for repair. It never bothered my so I didn't persue it.