Oddly, I spent a few hours on the phone with Paul Kovacks last Saturday. I even mentioned seeing this 1934 Lionel advert to him. In his book, Paul speculates that Madison made the 1910 pullmans.
One of the things Paul and I discussed concerned the different factories and the trains produced there.
The 1910 pullmans might have been made by Madison while the rest of the tooling was being sent to New Haven. Once New Haven was set up the knob roofed 18/19/190 were made in Connecticut. We didn't talk about 1910 pullmans, but it makes a great example.
One thing we did talk about was the question of the square cabs. The square cab locos were first made in New Haven. Were they ever made in Irvington? Ignore the 53 for this point as they continued through 1919. There are square cab locos - 1910,1911, and 1912 with features that date them from after 1913.
Here's a 1912 with Oval Lettering, no monitor roof and stamped steps.
Paul suggested that the unfinished square cabs ended up in boxes at Irvington and weren't assembled and sold until years later. This is because in NJ they set up the tooling to do round cabs.
A round cab loco is made with a press. A square cab is made with a brake and shears. The square cab is more labor intensive and based on my two years of high school metal shop results in more errors.
It makes sense that the Lionel in house service department would have assembled the obsolete items and then sold them in the show room. In Ron Hollander's book he says the repair people were very busing in the fall and winter, but bored in the spring and summer. This would have been an easy way to keep the service staff working and earning.
I think there were two periods were the service staff cleaned out obsolete items. The first is the 1915-17 period when the square cabs with ovals and the odd trolleys were made.
The second period would be 1923-27 when the pea green, peacock, mohave and red locos in both gauges were made. In standard gauge you can look at the binding posts to spot these.
This is why I want to know when Madison started buying rejects and obsolete items. Based on looking at the trains, I think the date will be in the mid 1930s. Certainly after 1927.
PS when I wrote the part above about the brake I tried to think of Lionel items made with a brake from after 1915. Can you think of an example?