I've found that Montgomery Ward "Airline" brand information is really hard to find. The main reason is that Montgomery Ward branded equipment manufactured by a variety of factories, sometimes even changing things within a model year. I have a couple Airline radios, and one is an old shortwave model that I'm particularly proud of. To obtain a schematic required a good deal of research, and even then, I was pretty much limited to reverse engineering. But they're pretty solid designs, so once they're working, it's pretty much a matter of keeping them clean and dry and replacing tubes and capacitors when needed, which usually isn't for decades. Tubes maybe a little more often, but you'd be surprized how long they last.