Well I did it. The result isn't perfect but considering how exasperating it was I’m fairly pleased with the result. Unlike ordinary wallpaper where you have to match in 1 dimension only, matching in 2 dimensions nearly drove me nuts.
I pasted the wall not the map. They stretched quite a bit during application - not sure whether that was a help or a hindrance. There are a few wrinkles here and there which became worse when I varnished. Used “decorators varnish”.