03 parts questions

[Randy A]

Digging through 1903 parts (not A3) I ran across a few that posed questions:
1. When did they use the small door butt plates that have the door and plate numbered?
2. When did they use the split shank sling swivels?
3. Did they ever use a stacking swivel with a flat on one side of the shank (slightly concave)? When viewed from the side the shank (part the swivel screw goes through) is "D" shaped. I'm pretty sure its not a Bubba job it's still got bluing on it. Otherwise identical to all other 03 stacking swivels.
Thanks,

[Gary L. Bush]

(1) 1903- 1905
(2) 1920s
(3) Rod bayonet Lock


Gary L Bush

[RCS]

My Rock Island s/n 64145 with RIA 3-07 bbl has the numbers inside the buttplate and inside the door, it also has the split shank lower band swivel (as my SA 160963 rifle)

[Randy A]

Yeah, after some digging I found that the split shank swivel was used from 1906 to early 1918. I think I've decided to sell all of my parts so it would be nice to know what everything is for.
Thanks guys,