Sorry to necro an old thread, but if OP @Shots is still hanging around the forums, I'd love to know what kind of latches you used on the top plate of this enclosure. It's hard to make out in the photos and I'm looking to build something similar now that I've swapped to a soft-top. Thanks!
I used box/case latches.
You should be able to search for "Spring Loaded Case Latch" to get a pretty wide variety of options. I don't remember the specific ones I used, but they were the same as the ones that were on my instrument case when I was on the drum & bugle corp.