@RogerCooper Here's a link to where you can download the map folder: https://drive.google.com/drive/folders/1OdfVWRsM6A-cSpxCrp_AwmBxt8eICnV2?usp=sharing
Just place that C:/Users/(your username)/triplea/downloadedMaps. You also might have to go to the map.properties folder in it and do the following:

This is now available through the in-game downloader.

@McMoney An interesting idea. If you provide a link I will try it out against the AI.

@GREGOREK said:

How do I define the points in the 'polygons.txt' file?

You dont.

Also there are no negative coordinates, the map is treated as if no wrap around existed, except for below.

The wrap around map edges will share a vertical map line, one to the left one to right.
You then need to stitch the wrap around TT/SZ manually together with connections in the xml like so;
<connection t1="Chihuahua-Durango" t2="Mexico City"/>
<connection t1="Acapulco-Chiapas" t2="Sinaloa-Guadalajara"/>
<connection t1="064 Sea Zone" t2="011 Sea Zone"/>
<connection t1="064 Sea Zone" t2="028 Sea Zone"/>

In map.properties this must be true
map.scrollWrapX=true

That should work.