Lyman 101, 102 and early 103 tang sights compared to later versions. This is a combination of pictures taken at different times.
The post & stem used on the 101, 102 & early 103's. The stem is offset in the post so the rear engages the threads on the elevation adjuster, there is a small rib pinched on the lower front of the stem to keep it from turning. The post is crimped on over a ring so this sights post cannot be disassembled further than shown. The base on this one has been cut down with a new hole added.
The early 103's had a smaller base than later versions which allowed a hole spacing as short as 1.125"... but the front screw was hard to get at unless the sight was partially disassembled.
The post & stem used on the later 103's, I believe the 101 & 102 had been discontinued by the time of this change. With this design the stem is centered in the sight and has a full length threaded rib that engages the threads in the elevation adjuster, the parts are held together by a threaded top piece with a notch for the rib on the stem so that it cannot unscrew with the stem in place - standard Lyman stems will not work, these sights require a stem with a full length threaded rib or the top will unscrew.
A small base 103 with with the 'later used' design for a Savage 1903 & etc, this design of post & stem was actually patented earlier.
The above small base sight compared to a later larger base 103, an 'SS' for the Savage 1922 & 23 Sporters, the ends of the base are supposed to be curled to fit the comb of the stock.
continued next post because # of picture's being over the limit.