I will trade pretty much every piston pumper I have (minus syringes) for that SC 600 and HydroCannon, probably more. I have a Gremlin, Tornado Strike, Thunderstorm, Swimways pumper, and Vaporizer, and maybe others. Reply back and I'll post some pictures.
Are you open to making a trade at a community war or meet-up? I'd be more comfortable with this than an exchange via shipping online. I'm heading out to the NYC area this weekend and driving down to the DC area in the middle of next week; if you're on the east coast, we could meet up and trade.
I'm back to Michigan. Perhaps I could go to CANE this weekend and we could make the trade there while Nerfing? If you're working that day, then perhaps pick off one of their other events and see if you can make it.