Unless he's makin the sledgehammer for swamps now.
Swamps doesn't "build" the sledge hammer, River City Turbo (no relation to River City Diesel) out of Arkansas builds them. Swamps is just a dealer & sells them. At the same time Unlimited Diesel, Carson, & many others also deal with River City Turbo & distribute them.
From my research the "Sledgehammer" is an S300 that is machined to fit a 76mm wheel. The problem is that the normal S300 is 60 something mm. Now picture a large wheel with a small shaft. I want to say rebuild kits are more expensive that normal because it's a one off charger & in the $400-$600 range. Don't hold me to that statement though.