OK... I'm wanting to venture more than a block from the house and had a vision of a hose blow-out after I get a mile away. Since I know nothing about the hoses on this thing except that they're hard as PVC, I used a multi-function tool (handiest thing since NiCad battery tools) to cut away the hose clamps. Drained the coolant, removed the top hose and heater hoses and was about to extract the thermostat for an inspection/replacement when I got interrupted. I was a little surprised at the crusty corrosion at the top radiator neck... I would have expected it to be a non-corrosive material. Looks like iron.