IDPA is not your standard trip the range, guns get dropped, guns get banged into things etc. While your gun may be in good condition now, the amount of draws in IDPA over a couple months will increase finish wear. While it's a solid gun, guns do and will break. Do you want to break your heirloom and have to replace parts taking away from it's authenticity?
I would not shoot it @ matches. I have a 1944 Ithaca 1911A1 (Cousin to your Remington Rand) and while I shoot it occasionally, I would not use it for IDPA or hard use.