I'm on the hunt for a lightweight two or three hole dog box, preferably with top storage. A guy I know has an older extremely light riveted aluminum box, but I have yet to find a company that still builds this style box or even an old one is good shape that's for sale. I want to be able to load and unload by myself. I'd sure appreciate any and all help.
I've got an aluminum skinned Heritage box, but like you said, it's not a one man job to get in or out. The old riveted boxes had no wood frame to weigh them down, just bent sheet aluminum riveted together.
Give Creative Sports Supply a call. They are fairly well known for building boxes that one man can load. I have a three holer I can easily throw in and out of truck. Its not diamond plate (not sure how heavy the ones on home page are) - assume they still make the lighter variety. creativedogboxes.com
I bought an Aluma-line box several years ago. Double doors, well ventilated, top tool box, excellent construction. I couldn't be more pleased with the performance of this unit. Manufactured in Iowa. I get a lot of compliments on it.