I admit Open source maybe too much to ask. (I can dream of it nonetheless.)
But consider the case of Freespace 2. Volition (the Dev) has released 99% of its source code in hope of promoting community growth. That game was released around the same time (a bit later than) SFC1... Now, as it stands Taldren doesn't appear to be doing anymore SFCs, (and be the time they come back, if they come back to SFC, the current SFC engine would be totally outdated. which needs rewrite anyway) It is an obsolete engine (it was quite nice for its day, but that's 3.5~4 years ago.) Who would copy-cat that anyhow? It will only enable the possiblity of modding, that's all.
Beside Sprite.q3 is (reputed) to be the art assets (i.e. button pictures) not the "code"/programming itself.
I appreacite you looking out for Taldren. But calm down. No one is stealing from them... It's just a simple request they may or (more likely) may not grant...
mags, if you didn't have access, then my compliments (yet again) about getting those multiple-weapon hardpoints working. (so they show repair and charging independently) It fits into the art assets perfectly!