Ruin the map as much as you can... tear it and put it in a dirty water (black tea is perfect) and dry it to be old and ready
Easy and simple you can make your map hundreds years old... all you need is some hipermangan (cheap, can be bought in any pharmacy), patience and of course a map.
Secret ingredient (kalium hipermanganicum) mixed with water.
This is all you need: hipermangan, sponge and a map
First hand... it looks intensive, but when it is dried it will be pretty soft
Second hand... its even more intensive, you must think that's to much contrast - don't worry just let it dry.
It's dry and contrast is better now.. problem with this map particularly is that it's drawn with colors that are not waterproof, but if the colors are waterproof you should "paint" it whole with hipermangan.
As you can see a little more hipermangan-water mixture on the edges give us really old and used look.
Grand finale with old map on a black passepartout.