That looks just like the "motor" on my Jun Air 6-4.
There's a Jun Air distributor for parts in Louisiana, I've had mine for a long time and it's the coolest air compressor you'll ever lay your hands on.
They use the same compressor head on most of their models, they just multiply the number of heads to get a bigger compressor.
FYI - The oil that the head requires must be distilled from Unicorn Tears based on the price.
This is the aftermarket version I picked up from Amazon, it's a lot cheaper and has worked well.
http://www.amazon.com/dp/B00E9BTJ3A/?tag=atomicindus08-20