Hi Jason,
One of the MLU members on this site has a Photo album of M152 communication vans and you should be able to find some photo's with interior shots of unrestored and restored interiors to help you out with your project.You can view it here;
http://http://www.signaltelecom.ca/M152%20I.html
If this link doesn't work,do a SEARCH and type in M152 pictures wanted by J.D. Baillie in the post war military vehicles forum
Hope this helps,
Derk.