Had locking hubs on many 4x4s. It is a great system, nearly bullet proof, and gave you the ability to truly disengage the front axles. Had them on Landcruisers, Jeeps, Land Rovers, Toyota pickups, 4 Runners and even a couple of Dodges and a few Chevies. Never had an issue on any of them. Greased the hubs and front bearings regularly because those vehicles spent a lot of time in deep mud, swamp and water.
There used to be quite a wide variety of makers back in the day. They were pretty simple to install, but my bet is probably only Warn and maybe one or two others are still making these hubs. Let us know how the project goes.