Back in the article on the Norfolk & Ohio I mentioned his use of Midlin track. This line of track was produced from 1939 into the 1950s (with a production break during WWII) by Fred J. Chemidlin of Scotch Plains, NJ, and was available in HO, OO, and S gauges.
Overall it was probably the most realistic track produced for use in OO and was a favorite among operators. It is a little hard to read due to wear but the box notes that this is “The Semi-Assembled Track Kit,” “The Only Track of its Kind,” and that “No Spikes or Track Gauge Necessary.” It was a unique, quality product. Besides the semi-assembled track (one rail was attached at the factory, the second was applied by the purchaser when the flexible track was fit to the location) you also received ballast and ballast cement in the box. This is the 24’ kit; it is marked at $5.20 per box.
For a closer view, this specific piece of Midlin track is unusual and was given me some years back by Bill Chapin. He thought this piece to be very interesting (he had several more) because not only did it have slots for OO two rail (their standard product), it also has a middle slot for a center third rail (Lionel style) and also a slot for another third rail that would result in dual gauge track in HO and OO! Someone had Midlin make up a batch of this unusual track for their layout. The slots are easier to see if you click on the photo for a larger version.
UPDATE: For more information on this track brand and a photo of Fred Chemidlin see this article.
For another view of the company in 1941 and photos of Chemidlin and his staff see this article.
UPDATE III: The other major product offered by any maker of track is turnouts. This photo shows a mint/boxed example, with the envelope having extra ties and rail joiners. Click on the photo for a better view. Their turnouts were excellent products of the type and matched the track itself perfectly.