Couldn't find a forum to solve this one. Old Hecla plug, possibly toaster or jug. Never seen one like this before, and would like to restore, but cannot see how it comes apart. Any ideas?
Stamped on earth strip:
V... CAT AC2 250V
7.5A PAT 142780

Toasters, jugs, portable elements for boiling water in a saucepan, etc. The latter were quite dangerous items because there was sometimes no way of stopping the whole element sliding into the water.

I'd be guessing if I was to suggest how to pull it apart but it may be that the rubber grommet on top of the plug in photo 2 might need prising off first. I did a search on the 'Net and Youtube and there's no info there for these plugs.

From memory, you prise those two metal prongs open with a screwdriver, and IIRC the prongs were earthed. As Brad wrote, those things were not high on the safety list.

Frankly, I would not bother. If I needed one I'd purchase the whole cord assembly from this place. Scroll down to CODE - - JUG CORD- CLICK

https://www.authenticlightingandhardware.com/electric-jug-element.html

Correct, the pressed metal springs also provided the earth connection. The more modern version, which can still be bought for some reason, is the same, although those plugs are held together with a 3mm machine screw and nut.

The site is interesting. I may add it to the Services Directory.

Just stumbled on this posting and that plug looks like the type that has a wire type circlip around the two bumps on either side.

Prise that clip off carefully and watch out that the thing does not go flying off somewhere you cannot find it.