My condolences on your loss.
Start here. The U.S. Caliber .30 Carbines
Rock-ola made 13 of the parts including the receiver. None of the original makers made all of 'em. So there's no such thing as an "all original" Carbine.
There's a free .pdf manual here. (Note the need for the provided UN & PW.) It'll tell you how to install a new front sight and the other bits. Biggerhammer.net - Miscellaneous Firearms Technical and Training Manuals
Gunparts(not the only source, so shop around.) has the parts for not totally stupid money. The front sight runs $13.75. $6.75 for the key and $2.75 for the pin. Needs a piece of wood, a punch and a brass mallet to put on.
Stocks and all the wee bits that go with 'em can get expensive.
Rear sights can be either the early flip sight or the adjustable. 99.99% of all Carbines went through a post war rebuild that mostly put on all the 'upgrades' approved during W.W. II. You can decide which ones you want and put 'em on if you feel like it. Usually as money becomes available.
When you get that far, think IMR4227 and 110 grain HP's or FMJ RN's.