🚀 go-pugleaf

Not sure wich mission I havewhat I believe is the DOS version and I am
playing the NOD single player game.  I am on the mission just after Seth
gets shot.  I take over the abandoned nod base, and even built a sizable
base across the river but the GDI base keeps pounding me, and I run out of
tiberium to mine.

Question 1) Do I have to sell the NOD building factory, it seems to me the
only way to get the initial engineer to start to capture the first GDI base?

Question 2) How do I prevent air strikes, since I don't get SAM sites if I
sell the NOD factory?

Any hints or suggestions are welcome.  I do ok, but have a high loss of
units, and low tiberium availability at the end.