I installed the SDK pointed to by
https://forums.civfanatics.com/threads/a-simple-guide-to-compiling-the-dll.405444/ (it is the one I have been using until now).
I have tried to run the installation of the SDK installer pointed to by
http://www.realism-invictus.com/forum/viewtopic.php?f=4&t=1375, but nothing happens when I try to run it, both when doing a basic run, run as admin, run from cmd, run from bash (including with as sudo), so I am not sure where to go from here, as the problem persists.
I did also try running the 2003 toolkit installer and get the extra .lib's, but that didn't change anything noticeable in the build log.
For thunderbird I am indeed trying to build the from the source as it is on SVN (from a version some weeks old), with the main changes being in the makefile setting paths. I need to ensure that I can compile the original before I try to add changes if I am going to have a chance of tracking down the problems.