I'm a big fan of postal history and have the 6 volumes of Robson Lowe's encyclopaedias.
In volume 5 (North America, published 1973) there is a page talking about the future release of volume 6 that would've covered the balance of the British Empire (ie: Caribbean, South America, Antarctica).
Volume 6 was finally released in 1991 but only covered the Leeward Islands. Lowe died in 1997.
In 2012 I wrote a book that covered the British Empire in the Caribbean and South America up to 1900. I physically made 3 copies. It took me three goes to make a satisfactory product. The only thing I couldn't do at home was the dust jacket. You'll see that it follows the format of the previous volumes of Lowe's work. It's a hard cover but doesn't have any gold lettering - I'm happy to admit that skill is beyond me.


I contacted Spink in London (as they own Christies as I understood it at the time) to see if they were interested in publishing but was told, in so many words, that there wouldn't be enough profit in it.
So, it sits alongside the other 6 volumes on one of my shelves and I've used it on many occasions. For me, it's nice to have all the information in the one place.
I know that it would've been out of date almost immediately as new discoveries are being made all the time but you can only work with what you've got at the time.
I can't help feeling that if profit were the sole motivation we'd have next to no philatelic literature. Self publishing is the way to go in my opinion, and when I finish my second book that's what I'll be doing. I can do the whole thing from home and print (and make) it on demand.