I had to get the hacksaw out in the end, leaving as much of the shaft as possible intact.
Once knob was removed a fine hacksaw was used to cust into the screw head just enough for screwdriver blade to get a hold and out it came- thread still good, not too much of a cut on the knob either. As it turns out, there was a brass extension shaft on the volume pot and so a replacement should be easy to source. Don't know if pot is still functional though.

Now the chassis could be removed from cabinet I could see considerable surface rust on the chassis top surface. Spent quite a few hours with small wire brushes, scouring pads, etc., removing as much as possible and the areas I could access cleaned up well enough.

Have used Novus plastic polish on the cabinet and it has come up well- it wasn't too bad to start with.

Now looking at the components to be replaced and having a hard time telling whats what. The Electros with values are straight forward but others I dont know. The good thing is I'm going to learn how to translate a circuit diagram to actual circuit.

I already have some new 630V caps but now to match these to the original values. I understand there are generous tolerances when it comes to cap values but not to go under original votage rating.

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Now looking at the components to be replaced and having a hard time telling whats what. The Electros with values are straight forward but others I dont know. The good thing is I'm going to learn how to translate a circuit diagram to actual circuit.

"

Tip number 1 - start at a valve pin and follow the path on paper and at the same time in the chassis. You'll soon get the hang of it!
Remember that when viewed from underneath, valve pins are numbered clockwise with pin 1 being:

For UX valves - the first clockwise pin from the gap between the two THICK pins.
For Octal valves - the first clockwise pin from the spigot key.
For all-glass valves - the first clockwise pin from the gap in the pins.

It helps if your circuit has pin numbers on it, if not, try this excellent site for tube/valve data:

https://frank.pocnet.net/