-s may be responsible for sound play (sub_42F2F4 in vshell.exe)
install or cdrom paths longer than 80 chars may crash the game due to overflows
gamefile.str does not follow the standard. it consists of two parts with two (maybe different) msg counts, see sub_40e380 in vshell.exe
the second separation char in the second part of gamefile.str has some meaning within the src
second separation char in campaign.str is for alignment (if !=0, then position is shifted n bytes forward)
investigate xrefs of dword_48D388, this may prove useful for getting info about Text class
http://www.gog.com/en/forum/red_baron_pack/windows_7_1/page1 => darkmono.vxd and the filenames => Red Baron 2 (RB3D) is likely sharing something with ES2 (same release year, both created by Dynamix / Sierra On-Line)