Having trouble with "The Crossing - Part 1b, Gun Assaul
 

I've put the p3 file into the main folder and I'm still not seeing it on the SP or DM maplist. Any ideas as to what may be wrong?

It's a DM map only. Error in the write up about it here as being SP. As far as I know it's not in any server rotation anywhere. I've updated it for Spearhead but never released that version. Maybe in a month or so after some improvements and tweaks I've learned from my Tractor Works map.

Oh, the Gun Assault map is AA only, so be sure to put the pk3 into the /mohaa/main folder. You should be able to load it and run around via the console '~' key, then type 'maplist'.