Late last season I purchased an SuperFlow MV-50 portable air compressor for airing up. The air gauge screws vibrated loose on the first use of the device so I decided to disassemble it, repairing the issue with upgrades.
Researching the model on the Internet I came across other sites that talked about modding the unit. The primary mod is opening the air intake. I did that plus upgraded the wiring and paid careful attention to piston-to-cylinder alignment upon reassembly.
Photos of the unit, with upgrade notes, are here: