Can anyone tell me what these fixings are called?

[Milliways]

And where can I get them?
Builders took a bed apart and we only have 1 of these D shaped bolt thingies in the bag of bits they left to rebuild it! Need it to hold a bolt in a round cut out.
Husband been to screw fix wicks etc and no joy.
Thanks for any advice

Actually, more googling found half moon bed washers may be what we need!

I think they are made specifically for your bed - not a standard off the shelf thing. Where was the bed from? Could you contact the maker and see if you can get replacements?

Yes, Bensons but closed for support until Monday. Have found them on Amazon luckily. Thanks