I've been looking around, but almost all of the resources I find are for RB3D. I'm trying to play the first game with my Thrustmaster T Flight HOTAS X, which works surprisingly well, but the hat doesn't change POV, and, more importantly, the throttle doesn't work.

I've found both of these work with RB3D, but I mainly bought this pack for the first game. Is there any fix at all?

You may need to make some changes in the .conf file, the way I have it is as follows:

[joystick]
joysticktype=auto
timed=false
autofire=false
swap34=true
buttonwrap=false

You may change joysticktype to ch to make the pov work and the throttle is still buggy, in the first mission it works good but in the mission after that it can only do full or no throttle but I have the aces version of this game not gog's so yours might work here.

you can also use ppjoy for windows or controllermate for Mac to allow your joystick to control those things

Also there are some custom patches and programs here:

http://www.gog.com/forum/red_baron_pack/red_baron_1_custom_patches_and_programs

XB146.ZIP in particular may be what you are looking for - I never installed it myself, keep meaning to, I'm just lazy :)