[runequester]

Im not sure if the pre-WW2 stuff is a huge priority, but figured this might be worth mentioning:

The american M2 60mm mortar will show up from 1930 onwards, but to my knowledge, this wasn't actually in army service until 1940.

From the Brit list, you can buy Carrier platoons with Bren carriers in 1930 as well, which should be 1934 or so.

Cheers!