Hello Fred
The early days of O scale are a fun and interesting period with rapid growth in technology and refinements among the models.
Many folks offered rail in steel and brass ... before the war . Brass rail disappears early 1942 as part of the conservation of war materials .
I have yet to make a study of the various rail codes that were available .
I'll post some photos of an outside 3rd rail layout, I was very fortunate to purchase
cheers Carey
Here is one ad for early rail
Carl Auel with special offer for 132 rail
cheers Carey