Hello!
your first solution with only adding the tga file should have helped already, weird that it did not;
of course your second try with adding the map the old fashioned way will work, provided the textures you might need are all in-which they should if the map work now...
concerning the Nomad, I have solved the problem myself;
on my modded WAW module, I have added the PBY Blackcat mod, which is not part of WAW yet..
with this mod in, the PBN does loose its bombsight again, which it has now by default, using WAW 20;
but I found the classfiles that are responsible for loosing the BS, remmed them out and now I have the BlackCat, and the PBN with working bombsights;
the better question concerning the PBN is why it was introduced the first way; it would have been better to introduce a stock PBY version as this would have been easier to develop further, but Oleg chose the PBN and thats it.
I have gread admiration for these crews who did the U-Boat hunting in the Atlantic, no matter what they rode in;
pretty much all of those bombers were large, lumbering targets that were not very maneuverable down low; add to this some aggressive sub skippers with a conning tower bristling with AA guns and you know how that must have felt;
those subs even killed a lot of Wildcats and Avengers from hunter-killer teams which were far more maneuverable;
for sfs extraction, I use a rather old program now - sfs extract;
it extracts the complete sfs file or only parts of it and the best thing is it conserves the file structure of the files inside the sfs...
for the time being, if you need the Burma map, leave your install as it is, it will not hurt anything and it will be upward compatible if Monty decides to release now WAW parts; just do not copy over the mapmods folder then

best regards
phil