An attempt for cleaning up the original image in a few steps.
Source Lazur URH
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
A pale yellow background pattern with vertical stripes. The stripes are partially faded. I think this background image turned out pretty well, especially those faded stripes.
Source V. Hartikainen
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
Abstract Ellipses Background Grayscale
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i
Source Firkin
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ