RWTF;
Your description sounds like a 2-Hook gun. It would have one hook in the frame bar which attaches to the hammer axle & another pivoted under the bbls. The two hooks engage one another for rotating the hammers back upon opening. Assuming this to be correct I would be suspicious of the '99 build date. Not familiar with the mentioned chart, but the large single hook was in common use well prior to '99. To the best of my knowledge whether or not a gun had ejectors played no part in the forend, "except" for a very few early ejector guns which had forend ejectors. The vast majority of ejector Lefevers will have the in-frame variety with nothing in the forend. Lefever forends will be found with a pusbutton release, a clamshell release (Deely & Edge variant) or a pull off forend with either a Metal or Bakelite Dogshead escutcheon, all in the center of the forend. Normally only the I/DS grades will be found with nothing in the forend center. If the area filled with the glass is round it was most certainly one of the bakelite dogsheads originally, in fact are you certain it is not one of these with the surface worn smooth, they didn't really hold up all that well. Any other shape than plain round it likely had a metal escutcheon. I assume it did not have one of the latching mechanisms, & is one of the snap-on; pull-off type.
From that era it runs high odds of being Damascus, chamber could be either 2 5/8" or 2 3/4", but either way would need proper loading, not current SAAMI loads.
