Gaseous - you don't have to acknowledge the dimensions of a MATZ (5nm/3000') in class G as it is a military structure but you must acknowledge the standard ATZ (2nm/2000') within it and frankly anyone penetrating a MATZ without talking to the controlling unit is asking for an airprox.
Grainger - I presume you would make your call on DEPCOM (122.95) as prescribed in the CAP when lifting in class G airspace.