Well I am using ebay UK and came up with these: https://www.ebay.co.uk/sch/i.html?_f...i+map&_sacat=0 and there seems to be plenty - so much so that I didn't look for the most up to date one but I have to think that one of them would have what you need. I don't think paper maps will ever go out of style - in fact I was looking for maps for the Pennine Way and the South Downs Way earlier and there are more than I expected. I will be amazed if you cannot find something.