Oregon saw boots. Size 12. Caulked. http://www.baileysonline.com/Footwe...Black-Tusk-Chainsaw-Boots---Caulked-Soles.axd I paid around $275 for them ~2 years ago. I'd let them go for $150.
Worn for 15 mins 2 years ago. Can't use because they are hard on my back and I'm in and out of vehicles and equipment all day. The caulks are sharp. They do work awesome on ice. Could use them to climb the side of a glacier!
Quite a nice boot. I never knew they existed until you posted this. They must be heavy like you said. Good luck!