Tin train cars had a variety of methods to couple them together, but by far the most common method was a coupler commonly called tab-in-slot. The tab from one car mated with a slot in the next. All of the train manufacturers used a variant of this method at one point or another, and all of them would be able to couple together, if not for one nagging detail: height.
For most of the 1930s and 1940s, Lionel used a latch coupler that was incompatible with the others–Lionel liked doing things like that–but they made a combination coupler for a while that had a slot in it to accommodate tab-in-slot couplers. Reproductions are available on Ebay. Get one of those for this car, and something that couples with the other cars you like to run, whether that’s an Ives snakehead coupler if you’re lucky enough to have a spare one, a generic tab-in-slot coupler, or another Lionel combination coupler.
But even when you change the couplers on the car, you’re still likely to have height issues. Here are some approaches to solving the height problem so you can run various brands of vintage trains together almost as effortlessly as people pick and choose between all brands of modern trains today.
Originally, couplers were usually held in place by bending the shank in one way or another so it couldn’t come back out of its hole in the frame. This was much more cost effective than using rivets or screws. But when you’re building a super-utility player, the additional cost of 50 cents worth of nuts and bolts isn’t much of an issue.
First you need to choose a donor car to modify. Pick something that won’t look shabby next to the cars you want to run it with, but get something common and inexpensive enough that you won’t mind modifying it. A Lionel tin O27 gondola is often a good choice.
Next, size the hole in the body and determine a machine screw size that will fit. A 4-40 screw fits an opening of .112 inches (2.8 mm); a 6-32 fits an opening of .138 inches (3.5 mm); and an 8-32 fits an opening of .164 (4.2 mm). A tight fit is helpful but not always necessary.
Now compare the car with the cars you want to run it with. If you’re lucky, you may find the difference in height is a couple of millimeters. If that’s the case, you can mount the car with a half-inch machine screw and one nylon lock nut, assuming the machine screw fits in its hole tightly. If it doesn’t fit tightly, you’ll need another nylon lock nut. Just insert the machine screw in the hole with the threads pointing toward the wheels, tighten it or secure it with a lock nut if it fits loosely, then put the coupler in, then put the lock nut on the end, tightening it enough to hold the coupler in place but leaving it loose enough that the coupler can shift up or down as needed to mate with different makes of cars.
Some makes of cars present a problem, unfortunately. Marx and Hafner cars sat lower to the ground than American Flyer, Dorfan, Ives, and Lionel did. To couple with those, you’ll need to use a longer screw, and add a couple of regular nuts on either side of the coupler. Then you can spin the nuts up and down the screw to adjust the coupler to match whatever other car you want to connect with.