Ah, you must be the fellow who just emailed me! We may as well keep conversation here, it'll get seen by more relevant eyes. Since it does seem you want to port to OpenGL, to my knowledge, it's not as bad as you might think. The difference here is that FSO was moved from D3D to OpenGL. Glide to OpenGL, to my knowledge, might be easier, although you may lose some of the nicer features of Glide during the initial conversion, as Glide was originally an enhanced subset of OpenGL. But OpenGL has moved forward and should be able to move past the capabilities of the Glide engine, even into the realm of shader support eventually. Taylor has been the one who has done the bulk of the graphics work on FSO. He may be open to working on a project with the prospect of getting reimbursed for his contributions through monetary compensation, I can't say. There are a couple other OpenGL coders around here. One, Hery, has stepped back from FSO but you might see about contacting him as well. The other coders I know of with graphics experience are still active here and would have to comment themselves on whether they want to/have time to help.
Will this source code become available to the public? I'd love to take a look at it.