Question on Lionel swing bridge 6-24111.

Maybe someone that does 3D printing could print a new gear. Finding the exact match gear is a long shot at best.

Old nylon/plastic gears get brittle with age. 

If it were me I would buy the North Lima gearbox and enjoy the bridge.

I guess it depends exactly how cheap the bridge was, but I'd probably go for the gearbox too, if it's still available. 

Agreed it would be much nicer if the discrete parts within these gearboxes were available.  I had a similar issue with a Nuclear Reactor accessory (though self inflicted - I wasn't gentle enough with the manual lever and I bent something inside), but that gearbox was still stocked by Lionel.  IIRC, it was $70 for that gearbox, but I was able to get it for half that during one of the "Open house parts sales" Lionel had been doing in November most years.

As to the original price on the Swing Bridge, these didn't do so well (seems many more made than pre-ordered), and they were blow out I believe 2 times.  I bought one brand new as a spare for $100. Before that, I think many dealers had been selling them at $160 from the first blow-out sale.

-Dave

If you can piece it back together and get some specs North West Short Line may be able to make it. They have helped make gears for the nuclear reactor. https://nwsl.com