Well, I have an update, if I was a doctor it would be a case of the operation was a success, but the patient died.
I replaced the resistor, caps and had already tested the nearby diodes
I have some more photos
First, the board with the resistor and caps removed, so you can see the carbon deposits
Then, the board after cleaning, showing some erosion of the board
I put the new components in, having made sure that each of the connection points had continuity to the right part of the board.
The machine was reassembled, powered on, and the machine was alive, with all the buttons and the display working correctly.
I then decided to run a final test by running through a wash program. the door locked, there was the sound of the discharge pump making sure the drum was empty and then after about 2 seconds a bright blue flash and bang.
The underside of the PCB is now fried but there's no real sign of damage to the top of the board.
and
Thanks for all the help, unfortunately on this occasion it looks like I have not been successful in my repair attempt. I don't think I did anything wrong, but it's always possible that I did.
I'm now on the lookout for a s/h PCB, but suspect I'm going to have to buy a new washer/dryer imminently before we run out of clean clothes.
Hopefully the additions to the original thread will be helpful for others. The service on the components I ordered on ebay was superb - shipped within the hour and next day arrival.
Thanks again