Lyman 48 selection is further complicated by the myriad of styles and dimensions that evolved over time. The earliest examples had the 'full block' base with the elevation screw's bottom end being captive against the inside of the long slide and with relatively small adjusting knobs and 1/2-minute clicks. Later the sight was offered with larger target-style knobs and 1/3-minute clicks as well, with a shorter slide as described in the post above. Still later, perhaps in the late '40s or early '50s, the 'full-block' sight was again modified to use a different elevation adjusting screw that didn't require a captive lower end. This newer sight's adjusting screws have 1/4-minute clicks but the visible knurled portion of the adjusting screws still retain the prewar look. This sight also retains the earlier rounded lower side of the elevation slide. The last iterations of the 48 had a shorter scalloped-out base that was relieved to clear the stock wood and was available with either smaller 'hunter'/'stayset' knobs or larger target knobs. These last sights also had squared-off bottoms on their elevation slides instead of the earlier and more attractive rounded-bottom style.
These are the major variations but I've also seen numerous sub-variations of these, e.g. with the horizontal adjustment scales on different sides of the peep and with fold-down peeps present in some but not others seemingly of the same vintage.
I have a few, a VERY few, parts for these sights. If anyone needs help I'll be glad to do my best to assist. I don't have any spare 48 sights, sorry.
Regards, Joe
