IMHO "restoring" it would be alot of trouble and money to make it "look" original, which it will never be again. Especially if you need an original barrel.($50-100)
Welding all 4 holes to try and make it look original after a repark seems like money not well spent.
Re-parking receiver and barrel - $150
Original barrel installed - $150 (barrel and install)
Replacement stock $50-150 depending on cartouches
Front and rear sights - $45
What is your correct bolt for 03a3 or 03a4?
If you make a 03a4 clone out of it you will still need to repark. Barrel? And I wouldnt worry about the 2 holes on the side from the peep sight.
Replacement C-stock or scant - $50-100, original sniper stocks are outrageously priced.
Repro scope, mount, and rings - $160
All these prices are round-abouts you will find.
Your getting into a lot of money to make it look like something its not.
It looks like you already have a nice sporter.
Shoot it, enjoy it for what it is, and keep collecting milsurps.