I mentioned this in another thread, but I’ve always felt that the US Airmail Route beacon system would be a very cool sub-package. It would take 15 period correct airstrips, and approximately 1,500 arrow beacons placed by geodata. Maybe throw in a few generic small town water towers painted with town name, maybe a building here or there with the town name on the roof. I’d fly it in the Carenado Waco.
It would be way too much work, but a package that recreates old Route 66 landmarks would be cool too. There are a lot of funky old nostalgic landmarks on 66. It was the nation’s primary cross country highway when it was constructed, so thousands of small entrepreneurs set up all kind of strange roadside attractions in order to get travelers to stop and spend money at their business.