I bought four Lionel 100 series cars today when I went and looked at trains. The guy had a bunch of overpriced repainted standard gauge which I didn't buy. I did get four cars for $60, and I also got a variation of the 83 signal with a mohave base and some loco wheels and parts for another $40.
I bought a 116 dump and three 112 gondolas. Two gondolas and a dump were different and I didn't have the signal. I have six with maroon bases but none with mohave!
One of the cars was a gray gondola with black lettering. I looked at all my 100 series cars. Most of them have no stamps on the bottoms, but when they do it matches the ink on the side. I did find a dark green 116 hopper, a light gray 116, and a dark gray 112 gondola with black lettering.
I think the green hopper is late teens, but the two gray cars are mid-20s cars based on the trucks having dimples.
I also found two orange 32 baggage cars - one with the understamp in black, one in gold. I have two sets of orange cars all cars have gold lettering on the bodies. The 35 pullmans have no stamps on the bottom, 5 cars - 1X baggage, 2X combine and 2X observation have black stamps. Only the one baggage has a gold stamp. and is an odd car in another way.
The 32 bagagge with gold lettering on the bottom has extra doors on the vestibules. This is a commonly found factory error, that I think only comes on the orange cars. The regular black bottom stamped car has no doors on the ends.
I also looked at my other 0 cars. I have no O gauge cars with black understamps. I have early body 610 cars in mohave with oil labels, and a matching observation with a gold stamp on the bottom.