That’s Bedder!
Luckily the 13mm size was on the other end of the spanner (mines not 12mm).
No problem with that funny spring washer , just eased the the sprung clip away with small screwdriver and pushed down on the clip with my fingers, when refitting again prised the clip clear and lifted up.
The resistance of the gas struts means that the bed no longer wants to fall on my head….in fact it doesn’t even lay flat anymore unless you climb onto it….might be different with winter bedding?
Lifting the bed up is a lovely experience now with no more bracing yourself for the big lift.
Great tip off Barry to use those heavier duty struts.
Fred