.
As I posted above, AFAIK the 22" bbl (if measured properly, down the bore from the muzzle to the face of the closed bolt,) & the takedown feature should make it a Model 1899D.
Your SN comes back as a 1920 vintage ( extrapolated as late 3rd to early 4th quarter).
Hopefully, maybe someone else here, with more Model 1899/99 experience, can help confirm my suppositions or post a different opinion.
.
Bookmarks