In half an hour over there I had four replies already, either wanting the uniform or directing me to someone who would. I wouldn't hesitate to give it to any of those who asked. So far they've mentioned:
--the American Military Museum in Charleston, SC
--Joe Blunt, as the representative for the USMC Historical Company:
--the Stars and Stripes Museum in Bloomfield, MO
I would also encourage you to save all the little bits of WWII paperwork, old ration books, newspaper clippings, etc. that you may find among his things. Too much of that gets thrown away, and sometimes it gives us a whole new perspective on what happened.
Oh, and here's Mt. Vernon's response to your kind thought. Cpl. Joe Marti and his unit are his Civil War persona:
Of course, being a hoarder, I want it all to myself (Mine! Mine! Mine!).
First of all, thank you for taking this seriously. WWII vets are still among us, albeit decreasingly, so the material culture of the time doesn't feel as rarefied as perhaps the equivalent gear from the CW does. When my grandfather was a boy, he remembers seeing his great-grandfather's Civil War uniform rotting in a root cellar in Nebraska. It wasn't important to them because it was relatively recent. We cringe to hear that, but I'm sure that was the fate of perhaps the majority of gear. What you're doing is both rare and vitally important to our country's history
I'm sure there are a fair number of folks here on the site (Brian Hicks comes to mind, though I 'm sure there are more) who are inactive Marines who would either take loving care of it or have knowledge of other places who will benefit from such an august donation.
So much of what we know about the material culture of the Civil War is due to folks like yourself donating items like this to research institutions/museums a la the Smithsonian/National Archives. Without those things we would probably all be wearing cotton uniforms and infantry privates would be sporting cavalry sabers. Oh wait. That's still happening. Just goes to show you, the people need to know!
Nonetheless, I'm sure you've come to the right place to find people who have the correct reverence coupled with the knowledge of just what to do. Good luck!
Cpl. Joe Marti
20th Maine Vol. Inf. Co. G.
Third Brigade, First Division, Fifth Corps
Army of the Potomac