What kind of lockons did Lionel make for standard gauge track back in the 1920s? Did they even use a lockon or was it some form of another mechanism that connected the transformer power to the track? The only thing I can find for prewar lockons are the UTC universal ones, but what were the predecessors to that? Whatever it is, I’d like to purchase one… if any exist!
I have several, all packed away for moving at the moment of course…[:(] or I’d take a picture for you! [;)]
But what you’re probably looking for is an “STC”. Here’s a listing on Ebay to show you what they look like: https://www.ebay.com/itm/265152410671?hash=item3dbc50b42f:g:2-wAAOSwlc5gldtU
You can usually pick them up cheap at train shows. (“Cheap” like a dollar or less per.) I have several and use them with insulated track sections to activate lineside accessories.