Actually a tutorial on building a campaign would be more helpful. You've done it. I'm now attempting one-but the directions in the manual aren't the best -OR- or putting an Iraqi Helmet on a Russian enlisted soldier for Afghanistan (I tried that months ago and SABOW kept crashing after about a minute after the scenario started.) OR putting that American Helmmet you made on Iranian Infantry.
M38 jeep *meh* save your brain power and resources. Just my 2 cents.
The other stuff is easy
The m38 model is nearly complete. Here let me dig up a pic in a second. It crashed with the helmet as it did not find the model. likely just simple config issue. DID you unpack the config from patch? That is the one you want. The easlier one will likely causes crashes galore as it is out dated. On the campaign. this has changed some since I made all mine. It is actually easier now as you can use open office spread sheets.