Old large map of Central and South Africa

Got this map which i never framed because it is fairly large in size approx 220x110cm, 86x43 . Got it for a while now but never found exactly the same so I could put a value on it. It has no inscriptions of the map maker or printer which is strange to me. Dates from 1919 and backed on linen. Probably a issue of the South Africa newspaper and probably printed in London ?? It also has many interesting and large trade advertising on the sides. Was probably hanging in a trade office or in a ship as a friend pointed out?? Can somebody help me with this one. It is maybe not that old to be valuable? Is this a rare map?

 

From my experience maps similar to this one can be rare but not valuable.
I have a decent amount of old pamphlet maps of London that I can find nothing about and when one comes up for sale on ebay or other sites it doesn't tend to gain a lot of attention. I'm not sure whether early 20th century maps of Africa are popular; if they aren't this might appeal to Ephemera more than map collectors. So to answer your question directly... It would appear this is a rare map and by rare I mean few copies were made or few are known to still exist.