That looks like a standard Leupold base or possibly a Redfield. You should be able to find rings just about anywhere. Brownells, Midway, etc.

Sounds like a fun project. I've always like the 99. Great guns.

Good luck and all the best.

 

Has anyone heard of these having some sort of special blueing? If so what's it called and how do I learn it? I just found a little bit of rust under the hand guard.

 

All Savage 99s after WW-II were hot dip blued. For minor surface rust, wipe GENTLY with any solvent and 000 steel wool. Wipe off the red juice and oil with a good gun oil. Once rust goes through the blueing, the speck becomes permanent. Don't agonize over it, it happens.
If you're going to mount a scope, you don't need the rear sight. It was probably removed because it interfered with the scope.
Those look to be Leupold rings. You're missing the top half of both.

 

As said above, you'll need to buy a new set of "standard" rings and any name brand of them will fit that standard base. Your base has a windage adjustable rear and turn in front ring. Height will depend on your choice of scope size. I prefer a compact size scope on most all my rifles in 1-4x20, 2-7x33 or 3-9x40. I'd look to utilize low or medium height rings on that rifle. The last M99 in .308 I had and just recently sold had low standard rings holding a Leupold 1-4x20 and it worked great for me.

As Jack said the rear sight was likely removed to accommodate a scope with a fairly large objective of 40mm or so. There's no really good reason to replace in my opinion.

Congratulations on getting that fine old classic and I hope you enjoy it for many years 👍

Almost forgot, welcome to the forum from the great state of Tennessee 👍

 

Does having the iron sight in a rifle like this affect its collectability or resale value?

 

Value or worth, is an individual preference.
There is a man somewhere, who thinks a Yugo from the 1980's is as fine as frogs hair.
If you can find him, he'll pay a lot of money for what others consider an oil leaking pile of scrap metal. 😉

 

Having the sights is entirely up to you. There is no collector's value in that gun at this time. The stock has been stripped of its brown stain and refinished and looks like a good job. You have the ultimate in 'using' guns. Enjoy it.