Help please Nosram esc?

[misterfixit]

Hi All,

This is my first post here. I raced along time ago (late 80's, early 90's) but I never got rid of loads of my gear.

I have this vintage nosram ESC. Can anyone help:
1/ Identify it?
2/ Does anyone have one?
3/ If you do can I be really cheeky, could someone open one up and let me know the two components i've highlighted in my second picture.

Cheers for all yourhelp in advance!

Richard