Compressor / mag motor control issues

Okay, I picked up a Dresser 5HP/80 Gallon compressor last year, and it's been working great, but last weekend I turned it on and it seemed like something was caught in the motor, it would turn for a millisecond, then stop, then turn again and just try to freeze up but eventually run okay.

I finally had time to look at it today due to the snow, and I think the issue is the magnetic motor starter/control. I took the guards off, motor spins by hand easily with no belts on it, but same behavior when I flip the breaker. When I watch it, there is a ton of arcing coming from the magnetic motor control, so I think the contacts need cleaned or the coil replaced.

But, I'm a novice when working with these type of controls, so looking for help. Is it possible to clean the contacts, and if so how would I do it? Same thing for checking or replacing the coil?

The motor control is a GE CR354AC, and I've attached some pictures if it helps.

Thanks in advance for any suggestions or instructions!

Scott