The sun is shining in Dorset today.
I took the plug out of Bumpkin's H head (it came out easily with washer attached) I took a photo, it looked like the photo I took of mine. Then using the vernier gauge
@Exige I measured to the depth of the hole to the seating and also to the start of the thread.
Back to my bike remove the mudguard, brakes and front wheel take measurements. There is 1.47mm difference, thus washer is stuck to seating.
Armed with some facts and more room to move, I (my son) could then screw the spark plug (welded to a rod ,2 turns through the errant washer and pull
Bingo out it came!
Thank you all for your help..
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