Savage Model 45 Super Sporter

I just got this rifle on an auction, and would like to know when it was built: The SN is 57XX. The mag release is on the right, alongside the mag, not a button through the stock like some pics I've seen. To release the mag, you just squeeze the flat tab and the mag drops into your hand. I got 3 mags with the gun, plus a fourth mag with no spring or follower. The rifle has original sights including a tiny U-shaped notch in the rear barrel-mounted height-adjustable sight and a bead sight inlet into an integral-to-the-barrel ramp for the front. It also has the original (I think) Lyman aperture sight mounted at the back end of the receiver. Along with these two setups, it also has been drilled and tapped on the top of the receiver for a Redfield one-piece base and has the rings installed. The safety on the right of the receiver does not seem to work, but the bolt can be decocked like an old single shot .22 by letting it down while pulling the trigger, and then re-cocked by pulling the knurled bolt out.
I haven't shot it yet. Does anyone have knowledge of these rifles as to age and value?
Thanks.

The Model 40 and 45 Super Sporters were introduced in 1928, but I'm not sure when they were discontinued as my reference book (written in 1938) just says they were still in production at the time of it's writing. As for value, it's worth whatever you paid for it - the collector market for old Savage guns (not counting the Model 99's and select rimfire models) is almost non-existent so there's really no established values like there are for say Colt Single-Action revolvers or Winchester Model 42 shotguns.

The 45's (checkered and 40's (uncheckered) don't bring the money that the Savage model 1920's do, usually they sell for around $300 in good used condition, and real nice one will bring $450.

Was the wood knotched out for the Lyman peep? If so, it didn't come with it from the factory.