I was hoping there might be someone out there that could help me identify the make and model of an air compressor pump that came on an old air compressor I found and am bringing back to life. I've been cleaning it up and would like to know what it is if I ever need to rebuild it. I'm not that well informed on air compressor pumps so it could be that it's not a compressor pump, but it's bee used as one for years. There are no markings on it other than the ones included in the pictures below. There's a date on it of 12/27/1961 with number 4033 and SCC.

I would really appreciate any help on identification or suggestions on where to go to identify it.

Thanks!