Winchcombe Cushions

All, Just enjoying our first 'multi-night' trip (1 x Britstop, 3 nights on sites) in Northumbria and The Borders. Currently relaxing with a glass of Bordeaux having spotted Red Squirrels at Kielder this afternoon, when, due to a lack of a TV signal, SWMBO decided to check where the plethora of soft furnishings fit (as you do!)
We have sussed out the bench seating/bed cushions both seats and backs, the square settee cushions and the 'triangular' settee end cushions which leaves us with the 2 oblong jobs :  about 60cm with a square cross-section of approx 14cm. They also have backing material so presumably are designed to fit somewhere specific?
Sounds trivial I know, however we seem to have sussed everything else out (although the Trumo Combi proved a challenge - thanks to Gromit for excellent link to UTube guide which I have consulted more than once!). Any ideas please?
Cheers, Andy