Rear A frame to De Dion axle washer replacement.

Posted the issue on the excellent Caterham and Lotus 7 owners Club Facebook forum and got loads of helpful advice:

https://www.facebook.com/groups/318610305307075/?multi_permalinks=1661592971008795&notif_id=1692654868517701&notif_t=feedback_reaction_generic&ref=notif

Torque spec is 81Nm, 1/2”UNF fastener, so a pair of slim 19mm sockets are your friends.

Chock the fronts well and jack the rear so as to get the chassis rails onto stands. That way the rear will be in full droop and you won’t be fighting the weight of the rear of the car. 

Be sure to not tighten it all the way until it’s sitting on the ground. A tad more difficult but still doable.

Use two washers in each side. That way they slide over each other which is better for longevity than one washer being chewed up by metal from each side.

Spare nylon spacers purchased from Ebay thanks to help and advice from the forum.