Does anyone have photos of the rear mag retainer for a savage sporter 23A? I need one for my dad's old 22 and have not seen what I actually need.

Be sure it's a 23A and not a 23AA (different guts)

Try the Savage collectors thread.

There are also parts catalog reprints available on ebay.

Try this:
http://www.gunpartscorp.com/SchematicDisplay.aspx?schem=/images/schematics/Savage_Sporter23A_schem.jpg&name=Sporter+23A+%28*%29

THINK (!!!) it's #33

The rear is part #34 - #33 is the front spring that pushes the magazine back to hold it in #34 which is shown going the oposite direction as #33. #34 also has the ejector - the pointed prong on the top - the point faces the front of the gun. I have seen some where the ejector and the magazine mount are seperate parts that are held by the same screw but I do not know if these were just a variation for the 23A or were for different models such as the 23B etc and would not work on a 23A.
Numrich Savage_Sporter23A_schem

The magazine is held in place by it's rear rib fitting in a slot in part #34 (not clear in the picture) and is held there by the spring pressure of part #33.

Like interthem said make sure it's not a 23AA.

Here is a picture I made a few years ago of the mount in a 1922 SPORTER - it's the same as a 23A other than the ejector was not a part of the mount but a different design using a seperate part that mounted in the side of the receiver, you can see part of the 1922 type ejector sticking out the left side of the receiver (to the top as pictured) -

I sold one of these a number of years ago and the first thing the buyer had to say was that the mag release was broken. It wasn't, as shown above, he just needed to understand that the bottom of the mag needed to be rocked forward to release.
It was a 23B, sure wish I'd just not sold!