Check this out ..
USMC History and Museums ... I haven't looked at any of the links for this page yet, but it may have some stuff online re: photos, essays, unit histories, etc. Look under Historical.
Where do you live, by the way? The current Marine Corps Recruit Depot Commandant in San Diego,
Huly, was my Series Commander in 1972. Maybe, I can try and get ahold of him if you're in the SoCal area. I was a Platoon and Series Honorman in his series back in 1972. I know he wouldn;t remember me, but ya never know. :-)
The main site for the USMC is
http://www.usmc.mil