[morzh]

Terry has just told you what to do - replace the socket, there is NO saving it. The transformer might still be ok.

BTW it does look the socket has a notch for the key in the right place, you can see it about 2-o'clock, that how I think the tube should be inserted.

I would check the transformer first. I would also disconnect that socket (having taken a good photo first and labeling and insulating the wires) before doing that, plus removed all the tubes.
If it is good:
After replacing the socket - full recap, then the rest.