IIRC the original issue on that gun was a buttplate, not a pad. That's an older 11-48, since it lacks the flex slot in the receiver that was added later in production (and continued with the 1100/11-87) after Remington found out the receivers tended to crack at the back of the bolt handle slot when the gun got shot a lot.
I'd say the stock was indeed shortened by more than an inch if it's just over 13" with a 3/4" pad installed. Spacers are a possibility, with a new thicker pad. Or a replacement stock might turn up on eBay or somewhere, if you shop around.
I tend to shoot relatively short stocks since the 'house guns' here are fitted to my wife- with 12.5" LOP stocks, and I wear a 37" sleeve at 6'3". Try it as is, just put your thumb over on the knuckle of your trigger finger and see how that works (keeps you from bopping yourself in the nose with your thumb when it recoils). If you can adapt to the gun, no need to adapt the gun to you... . Much easier done with a too-short stock than a too long one.
BTW, I don't think that stock really needs any more refinishing either... fwiw...
Stay safe,
lpl/nc