I think there is room for as many as two towers on this block.
Do not touch Briggs. Period.
North of Briggs, obviously Kimbrell’s can go. Keep 50’ of the adjacent buildings facing both Fayetteville and Salisbury. While facadectomies or 10’ depth preservation to me is not adequate, keeping 50’ facing each street is, to me, enough to preserve the historical character of the interiors of these buildings. The block is 200’ deep, so that leaves a mid block footprint of 100x100 which is plenty for a tower. Parking would be accessed from the Kimbrell’s spot on Salisbury.
South of Briggs, I would be willing to lose the back (Salisbury) half of the building south of Big Easy if it meant connecting the Big Easy spot with the vacant lot behind Mahler. That leaves another 100x100 space immediately fronting Salisbury.
100x100 is a bit small of a footprint for an office building, although I think it could work. I certainly wouldn’t want the footprints to be any bigger than that, so if it doesn’t pencil out as office with 10ksf floor plates, then resi-only it is.