With Sears compressor manuals, there are few specific model manuals but rather a general guide for all of the similar compressors given when bought new. I see a maual for sale: Sears Craftsman Instruction Manual Oil Lubricated Single Stage | Etsy
The pumps are made by DeVilbiss and you can get more information on pump parts searching for "devilbiss" parts. the tank and accesories can be searched by the electrical motor brand, general compressor switch, etc. Sears did not have anything to do with the manufacture of the compressors they sold but simply labeled other manufactures like Devilbiss, Sanborne, etc. You might have to bend your own handle, good luck with your search.
Strange coincidence. I have a 919.15678 compressor too. I have been prowling the web for information on it, and your post showed up in a search. You'll have better luck in your searches if you add a zero to the end of the model number, e.g. 919.156780. Here is the manual and here is a parts listing for a model practically identical to these, for what they're worth. It is the 2 horsepower model. Not a lot of parts are available for this unit. It's a bit old now. Somewhere on that compressor is a data plate that may provide a clue to what the actual manufacturer's model number is. If it's Devilbiss, there is a good chance that parts can be had for it. Same for the motor.
One word of caution. As old as these things are, internal rust could have weakened the tank, making it a potential bomb. You should do a hydrostatic test on it to be sure it's sound enough to hold pressure.
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