Yowser- yeah, that Shipyard model is nice... and looking at the drawings and diagrams, I'd say it'd be a pretty easy unit to do a conversion-test on- the primaries could be wired right at the voltage-link panel.
I imagine they're worth every dollar one pays, and they're worth a whole lot...
My latest 'shipyard' unit... is a P&H generator driven by a six-cylinder Chrysler flathead, made in 1944... Looking closely, I'd say that P&H probably made many of these just to provide power for electromagnets on their shipyard cranes, but found that a variable output would make it suitable for welding, too... It has yet to speak on it's own accord, but the carb has been thoroughly cleaned out and reinstalled, all the gunk washed off (now I can see the distributor), and I've verified that everything turns as it should... it's waiting it's turn to be forklifted into the dry, warm, illuminated shop, and set on cribbing to get the doctor's eyeballs...