This scope does have the guide rail.
Bob

I've always rust blued the tubes on any old scopes that are steel Bob. And for removing small dents I have a piece of old round shaft I turned down to slide inside the tubes with a taper on one end to help it get past dents. Once pushed past the dent I rest both ends on wood blocks, and use my brass hammer to massage the dent out by tapping on it from the outside. It works fine as long as the dents aren't sharp hits.

No dents in this tube except the one Franks is referring too.  If it did, as you described, it would be the same as fixing a shotgun tube.

The interesting thing, on the subject of the ocular tube and the locating bump.  It appears there is not a corresponding locating point on the ocular tube, specifically made to fit the bump.  I expected a small cut out.  It appears the factory just pushed the tube in and let the tube bump form its own position in edge of the ocular tube.  Just enough to hold the ocular tube from rotating, along with not allowing it to move longitudinally in the main scope tube.
Bob

I must have read this wrong?

bobw wrote on Sep 16^th, 2024 at 1:28pm:

Frank, that’s exactly how this scope is.  The dent or dimple, actually pushes the side in so the threads would not work to remove the front lens.  I noticed the deformed side and was going to push it out when I realized what it was and was for.
Thanks for all the help.
Bob

My Stevens 438.

Thank you, sureshot.

I've never had a Stevens 438 apart but, if you could unscrew the cap on yours, I think, it should also have a ocular lens tube. If you could take that out, and look at both ends, see if it looks like the Lyman ocular tube that I picture, regarding how the lens are held in the tube.

I'm picturing a Lyman 438 and a Mossberg 4X. Note that the 438 lens are held by the threaded fastener and this is the end that goes against that "dent", it is actually a stop and the cap, holds it against that stop.

On the Mossberg, the tube is reversed, the threaded cap, holds the lenses in place and the end cap, captures the lens cap, to hold the lens tube in place.

I only have two 438's but, I have at least 20 Mossberg and Wallensacks. I can take the lens tubes from the Mossberg and Wallensack and put them in the 438 and visa versa, you can't hold them in place, because the end caps are different but, the view through the scope is the same.