Chama Roundhouse pits

I am seeking information on which stalls had engine pits in the Chama Roundhouse. I have searched and reviewed the numerous posts regarding the roundhouse. I have read that the pit in stall 9 (using the numbering convention of #1 being closest to the river and assuming the original 9 stalls) was widened, most likely to easy work on outside framed engines.

I also read that when the first four stalls were removed in 1945 that the order was for the removal of four stalls and three pits which would indicate that one of the stalls, 1 thru 4, did not have a pit. My quest is to identify which of the stalls had pits and which did not.

Any additional info to aid in modeling this structure would be welcome.

Robert