With some minor fussing, this cylinder will fit the H20-2 bezel for the L-54 and L-55 locks from the 1940s and 1950s in Airstreams, Spartans and a few other trailers.
It is just slightly larger diameter than the original so it requires you to file out the hole in your lock's chrome bezel ever so slightly to make it fit the new cylinder. It can be done with a hand file and will not change the appearance or structure of the lock.
You will also need to shorten the hardened steel square shaft on the cylinder by cutting it with a cut off wheel. To prevent binding on Airstreams, after cutting the shaft to length, grind the end of the shaft to the same shape as your original shaft.
Finally, when installing the square shaft in the lock body, you can insert the square shaft to any of the four orientations. Note that only one of the positions will make the lock function correctly, so experimenting will be necessary.
If you are ordering two or more cylinders, please let us know if you would like to have them keyed alike.