I’ve just come across your thread.
If you have seen it it, I thought you might be interested in an addon we have been developing to recreate several of the airways with their arrows, beacons and landing fields in the correct locations.
Our dev thread is here - [Updated] Arrows Across America: fly the US Air Mail routes 1926 - 1934
We are close to releasing version 3, which will include four of the 34 contract air mail routes.
The big onef for is will be the east-west route you have mapped.