1920s antique air compresser

i found a antique air compresser cleaning out my grandmas basement, and since she doesnt need it anymore i took it. it is a Atlas Sprayer made by k.j. Miller Corp. 115v ac or dc 1.12 amps 132w. i plugged it and it works fine,just vibrates a lot. and i hooked it up to my airbrush and it sprayed paint fine too. Ive looked on the web and these go for about 300, but i am looking to get $200 b/o for it. made of cast iron

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