One of the smallest twist-nuts is Ideal #71B. Usually requires pre-twisting/double over, and twist again before installation of the twist nut. Wire I used was 20 gauge control wire. DZ1000 on the layout, DZ1008A relay module used for dead-rail powering under the layout, (pictured).
Wiring for Seven (7) Push buttons. Lionel SC-2, connects at least six (6) of the turnouts, to the Cab 1 handheld remote.