This should help in setting up Pirates and The two Desert Combat mods.
Battlefield was made incredible by mods in my opinion. I've collected the three we played with the most, DC .7, DC Final, and pirates. They are included in the link above. There are a number of others still online, hosted here. We may mirror some of them to make sure they don't become lost to the internet at some point!
This stem may sound silly but I've found you need to have Battlefield 1942 running before you try to install the mods, we have run into issues when skipping this. Simply open the game, play for a minute or two, then come back to install these.
Pirates should install without any issue, i'll post any updates here if that changes.
Install 0.7 first then follow with Desert Combat Final. They include different maps but combine in the game.
All done, let's play!