Allied Propoganda Leaflets – can you help?

Can anyone please help me to discover what the market value would be for Allied propoganda leaflets, as dropped over German held territory circa 1941-43, would be worth?

I have a friend who has some that his Wing Commander father acquired somehow during the war. There are four, all different.

Three are about 212 x 138mm, on ever-so-slightly yellowing thin newsprint paper. They’re printed in black on both sides.

One is headed up ‘Englands Antwort” on one side, and on the other side “Wir Fahren Gegen Engelland!” with a diagrame of Europe with RAF and “Von USA” bombers over the continent. it is numbered 515, I assume the official document number.

The second is entitled ‘RAF V’ on one side and “,, Von der Maas bis an die Memel” on the other with another diagram of Europe showing how far bombers from Britian could get in 1941, 1942 and 1943. Numbered 508.

The third is titled “Hitler oder Roosevelt?” and the other side quotes a 1917 speech by Hindenberg, followed by a 1941 speech by Hitler. the document number is smudged a little but looks like 498.

The fourth leaflet is bigger, 214 x 270mm, on better white newsprint. It is document 512 and entitled ‘Englands Kriegsziele!’ on one side and the reverse talks about and has the signature of Roosevelt.

Anyway, my friend wants me to sell them on his behalf but I do not know what their value is. Can anyone advise approximate market values for genuine propoganda leaflets? Thanks.