Found myself on a western Minnesota lake doing some destructive testing. Rough ice newly defined. Got caught in a 35MPH gust as I was doing a downwind tack through deep wet drifts. Snapped off the Chinook 19" mast extension just below the mast. Rebuilding it with someting less flimsy than thin walled aluminum should be fairly straight forward. Unfortunately, the broken extension led quickly to a broken mast just above the hound, also snapping off the "top mast stiffener" inside. My fault entirely for not disassembling pronto. A nice guy from a shore cabin came out in his 4-wheeler and towed me the mile back to the car. There's something to be said for sailing in populated areas.

Beefing up the mast extension was indeed quite easy. 1 1/2" EMT (electrical conduit) is a near perfect match. Two pounds heavier, maybe 5 times stronger. Picked up a 550cm Gaastra mast on ebay that actually matches the sail's (12m YES) stiffness recommendation for a much better shape than the broken Powerex gave.
Current shop work is replacing the 11/16" front chock pivot (bent again) with 7/8" Stressproof rod and bronze bushing. On the dirt boat, the 5/8" axle/bolt (also bent) is being upsized to 3/4". The 1/4" steel axle plate (6"X8" with 9 through bolts) shows no deformation so far. A 3/16" steel plate tried in the past was inadequate.