The Nikon Professional cameras were made to go 150,000 cycles before requiring service. The Copal Square cameras were made to withstand 50,000. So killing a shutter after only 600 rolls of film seems low. It is possible to damage a copal square shutter by winding too quickly when used on slow speeds.
I would think it more likely that the camera needs a general CLA rather than the shutter replaced. I have had jammed Nikon F's and F2's that come back working fine after a CLA but with the same shutter. I have had shutter brakes replaced, and other parts that need lube jobs. I even got my Pawn-Shop rescue Nikon Ftn ($60) "beater" working again after a good cleaning with Ronsonol. It was so sad: I finished a roll on Christmas with a new/mint Vivitar series I 135mm F2.3 lens and the camera jammed on the very last picture of the roll. It gave its last to get me to the end of the roll. But now its BACK!