Sudsy, that tool has been hit by a hammer and hit hard judging by the mushroom I see in the picture.
If you take a file to the back end of that iron, it is soft. Same file on a calking iron or a chisel you'll find hard steel.
All I'll confess to is once when I was in kid prison I got a real bright idea to chop open and melt down a lead acid battery for the lead. That was long ago when batterys had hard rubber cases and pitch tops. That was not one of my better ideas, curdled the paint on the shop wall, which I got to scrub and repaint. The fumes drove me out of the building.
Good thing was Herb just shook his head and said "that's how boys learn". I also learned from scrubbing & painting to not melt things I didn't understand.
Far as block tin is concerned, that's a low melt point material, generally smoothed on bowls and such with a sheepskin pad. Sheep fur burns at around 1500° ignition point. As I recall, there is still 1 company in the US still blocking tin on cookware, and they do repairs.
Flying molten lead generally ain't real bad. Lead tends to act like an opening parachute as it flys, and cools rapidly. If it lands on bare skin you can generally figure a second degree burn, similar to a Sunburn.