I finally got the whole scheme together. The track runs around the room, over the door and across the windows. Two trains alternate, one running while the other waits at a signal.
One train is a Lionel General set, modified from a 2- to 3-position e-unit and with a rectifier whose polarity can be selected. Although that is locked out for this setup, it allows connecting the two motor field windings in series, to slow down the motor. The coach lights are dimmed by being wired in series, the headlight by a piece of shrink tubing on the bulb. I added the ATSF baggage car to the train, which is 8701, 9553, 9541, 9551, 9552.
The other train is a little 4-wheel ETS diesel, modified from 2-rail DC to 3-rail and with an American Flyer e-unit installed (also locked out), LED headlights and running lights added, and the same selectable rectifier scheme. It pulls two ETS Czech boxcars, one of them a green and white Budvar beer car (the Czech Budweiser) and the Lionel 5704 American Budweiser in the same colors coupled to it.
The trains are powered by a fixed 16 volts from a 300-watt American Flyer 30B transformer, through two parallel Lionel model-81 rheostats, each in series with a rectifier diode so that it controls only the train with the matching rectifier polarity.
About 2 feet of track in front of the signal is the stop section, with both running rails isolated. Before that is 6 feet of normal track and, before that, about 7 feet of control track, with the isolated rail wired to the running rails of the stop section and to the common terminal of the Lionel target signal. The green lamp goes to the center rail and the red lamp to the normal running rails. The green lamp is shunted by a no. 57 lamp completely enclosed in shrink tubing, to insure that the default signal is red but not emitting any light itself.
The corners are spirals, with two 22.5-degree sections of O27-profile O54 flanking a 45-degree O27 section, screwed to half-inch plywood. T