Outstanding find, Eric! Amazed to see that the CI&L once had a seven-track yard alongside Lyman St. between Douglas and Carroll Sts. (about where the brick joint Erie/MON depot used to be)!
Too bad they don't cover South Hammond. I suppose that's because back then, that area was way out of town.
I've attached a scan of the best map I've seen in the Hammond group. On one sheet, it shows the MONON's downtown triangular stone depot and its freight house, plus the frame Erie/C&O depot across the tracks (which burned down around 1940) and at the bottom, the NKP depot.