Greetings, commanders!
I had a demo years ago, from a videogame magazine disc, and I'm pretty sure it had only the three GDI missions. I'd have played the hell out of the Nod missions as well, if they were included. Until today I had no idea there was a demo with both sides playable.
Nowadays not even demos are what they used to be...
I'm Czech, in case it helps your research.
Glad to see there is still someone interested in original C&C after all those years.