Recently I purchased a Model 20/26 which, of course, has a Lyman No. 54 sight mounted on the bolt tail block. It is a .250-3000, serial no. 12868, so it was made close to the end of the production of the 20/26. (I haven't received the rifle yet, so this is based on photos from the auction house.)
Stroebel's book shows only one style of the Lyman No. 54, and it doesn't mention a second style. The first style has the elevation adjustment knob on the right side of the sight and a windage adjustment knob on the left side of the sight. My limited research shows this style sight on Model 1920s with the following serial numbers: 5905, 8396, and 10018. This style is also on iskra's early 20/26, ser. no. 10640.
The No. 54 on the rifle I have coming has the elevation adjustment knob on the left side of the sight, and the windage adjustment is now on the right, but it is no longer a knob. It appears that there is a slot in the end of the shaft on which the aperture is installed so that the adjustment would be made by a small screwdriver. I have also seen this style No. 54 on 20/26, ser. no. 12057.
Does anyone know when this change was made? Was this change specifically for the 20/26? (If so maybe the first style was used up on early 20/26s like iskra's.) Other ideas?

I have some data on that:

10624, 250, 20/26 marked "Savage 1920 Model", M54 (knob on right), long blade

10872, 300, "Savage Model 20", M54 (knob on left), long blade

The change appears to be between those two serials. Earlier serials on right, later serials on left.

You have narrowed it down more with the 10640 serial.

Did they stop using the early style when they changed the stamping to "Savage Model 20"? We have 232 rifles to look for to verify one way or the other.

PS... the "Savage Model 20" is on 10727 but I have no info on the sight.

Good info. Thanks Rick.

I don't know when Lyman started selling the #54 sights, but it must have been early in the 1920 production run, as the tail blocks were factory d&t for them early on.

Correction: The serial number in the first line of the original post should be 12878.

As stated in my original post, I thought there were two types of Lyman 54 sights for the Model 20. The early ones have knobs for both adjustments with the elevation on the right and windage on the left. The later ones have a knob for the elevation adjustment and a small screw for the windage adjustment with the elevation on the left and the windage on the right.

Now along comes this rifle: https://www.gunbroker.com/item/1031573881 with what appears to be a third variation of the Lyman 54. (Photos 4, 10 and 20 show the sight well.) Note that the adjustment locations are in the same position as the early 54s, but the windage adjustment is now by a screw as in the later style. Was this a transition style between the two described above or ???

Given the work done on the rifle and that the rear sight style was changed a couple of years earlier, at around the 106xx to 108xx range, I would not assume that the sight is original to the rifle or unmodified. If you can find another like it in the 12811 range then I would start digging.

Good eye.

Just saw a live auction for a 1920, #8836. It too has a Lyman 54 with the elevation knob on the right, and the screw windage adjustment on the left. So, I'm beginning to think that there are three variations of the Lyman 54:
1. Elevation adjustment is a knob on the right. Windage adjustment is a knob on the left.
2. Elevation adjustment is a knob on the right. Windage adjustment is a screw adjustment on the left.
3. Elevation adjustment is a knob on the left. Windage adjustment is a screw adjustment on the right.

I'm sure #1 was the first style produced. I think #2 was second and #3 was third, but not sure of that.

Might the knob be broke off? Just thinking out of the box.

No, one of the photos clearly shows the screw type windage adjustment. I didn't want to include a link since it's still a live auction.

Rick, I'll send you a PM.