The above is the only provisional marine corps unit I could find that served during World War II. It consisted of the 22d Marines - later joined by the 4th Marines - with service and support units. The brigade later formed the nucleus of the 6th Marine Division.
The building of facilities for marine corps units - temporary and permanent - was usually performed by organic marine engineer battalions and Seabees (naval construction battalions).
The ability of a company-size unit to build a facility to accomodate 15,000 men in three days sounds pretty far-fetched.