On Tuesday, 23 April 2019 18:36:46 UTC+1, D.M. Procida wrote:
Needless to say it seems to be impossible to find sprung mattresses in
that width (I have found a company that makes custom-sized foam
mattresses).

A quick google suggests quite a few places will make a custom size spring mattress

eg

https://www.oddmattress.co.uk/price-...tress-pricing/

Custom width is the next size up + 10% for reduction, custom length +20%.

"Sprung mattresses are usually increased or decreased in size by removing rows of springs from a mattress. Due to this custom sized beds with springs are usually increased or decreased by the dimension of a springs width. On average this is 75cm (3€³)."

https://www.prestigebeds.co.uk/2017/...tom-size-beds/

Owain