Open Inventor Port - can redistribute tk.c, gltk.h, GL?

I finished a port of SGI Open Inventor 2.1.5.6. I’d like to upload it to
qnxstart.com etc. It uses the software Mesa rendering provided with RTP 6.0.
Since the Mesa develpment package is not included in 6.1, I would like to
include some headerfiles (specifically /usr/include/GL/*.h and tk.c of the
Mesa example) in the distribution. Is this possible, or do I violate any
licenses?
Markus