K-Line made a small turntable / speeder shed accessory #42409 "SPEEDER SHED & SPEEDER". I paid $92.95 + $8.05 shipping for a total cost of $101.00 in 19__?? .... the dealer was GRZYBOSKI.
The K-Line speeder has people that are more G scale than O but I plan to run any of many of the SMALL, more scale looking Lionel units that have reverse units as they will fit on this short little "TURNTABLE". The track is compatible with the Lionel traditional tinplate three rail track, which is what I use on my layout.
This #42409 even has the switch controller that looks like a Lionel turnout switch controller! No MUSS, NO FUSS. NO cake pan needed. All done for you and works perfectly every time, to turn your little tank engines 90 degrees so the can drive into the speeder shed and then back out at your command!
Motorized units that might work are: #1845 #59 Minuteman unit, #28650 NYC 0-6-0 Dockside Switcher, K-Line 2630-14 US STEEL PLYMOUTH SWITCHER, #21230 RINGLING BROTHERS PORTER SWITCHER, or any of the RMT BANGS or BEEPS. I have NOT confirmed these WILL FIT yet. But I believe they will and these units have REVERSE UNITS, unlike the bumper GANG cars. Lionel's small speeders, rail joiners, and MOW Command TRACKMOBILES are another possability.
I was VERY surprised that the # 42409 accessory was not HUGELY POPULAR! And that they ended up on "blow-outs". Maybe it was because it was during the end of K-Line and folks thought all their product was dead & undesirable.
Paul Goodness