Source for Small Boxes to Shoulder-Carry Film Holders

I need a box for a very specific purpose: to shoulder-carry four 5x7 film holders in an upright orientation. (Already have and love two RPT cascade cases...but this need is slightly different).

It needs to be as follows:
Height: 9 1/2 to 10 inches
Width: 6 1/4 to 6 1/2 inches
Thickness: 2 1/2 to 3 inches

Hopefully made of molded plastic - thin, strong, light. As close to the above dimensions as possible...although if oversized I could add some padding.

With hinged, gasketed (water proof) lid...with some kind of side mounted rings for a carry strap.

Cannot be a metal ammo box...too heavy!

My first thought is that there's gotta be something out there, maybe made for something else...that's at least close to the above.

Then again...maybe there's some outfit which makes such carry boxes in various sizes?

Any thoughts? Thanks!

If you have a Container Store nearby, you might browse there.

I have a couple of small, vertical shoulder bags (one or both from REI) that would probably hold 3-4 5x7 holders. There in another location, so I can't be sure. But check out REI and others.

There's also Gearbest and Banggood for inexpensive "stuff" like:
https://www.gearbest.com/sling-bag/pp_1706989.html
https://www.gearbest.com/sling-bag/pp_1666080.html

FYI, you can also get plastic ammo cans, but I think a soft case is best for shoulder carry.

http://www.reallyusefulproducts.co.uk/uk/

This outfit has TONS of sizes, I got one at the Littleton Staples to hold all the film holders for the Epson 700 scanner, an odd size. Staples only has a few sizes on the shelf, but you could get a feel for how they are made and order one in if you find a good size. Sturdy boxes, much nicer than most of them I’ve come across.

There is a US version of the website, I missed clicking on that on this iPad.

Would love to know more about your application John. It's a bit hard to visualize.
Are the RPT Cascade cases like the Gnass film holder case?
I have one of the latter and used it yesterday with an Eagle Creek contoured shoulder strap. It was a relative breeze; almost forgot it was there.

A Cascade case is a joy to use...if the conditions are right. As for the "Cascade" feature...if you can visualize a long, flat case - with four zippered compartments placed evenly down the cases length...each of these compartments containing one film holder - this would be the "cascaded" configuration. The entire arrangement folds onto itself, so that the film holders now lay atop one another but still protected in their compartments...and a Cordura flap now wraps around the "case," this flap then being secured to itself with velcro. Hang-loops allow the case to be hung from a tripod...in both folded and "cascaded" configurations. Genius!

For me, the RPT Cascade cases work best if I’m just out to photograph. Two 5x7 Cascade cases fit nicely stacked at the top of my RPT P-3 backpack…along with lenses placed below this, and finally the camera at the bottom…with folded dark cloth laid out over everything in the main compartment. Meter, filters, etc. fit into the top compartment, and “extras” like lunch, water, rain gear, etc. fits into two auxiliary side pockets. I do find it easier to hand-carry my Gitzo CF tripod.

When I decide to set up for a photograph…my tripod gets set up first, and my head becomes a “camera” over the tripod’s head - so things are generally visualized and pre-set before the camera gets mounted. I will then typically hang a cascade film holder case (in its “cascaded” configuration) from the tripod prior to mounting the camera. Overall a great setup…and ideally this is how I like to work when possible.

But…when I’m either truly in a hurry, wanting to travel light, backpacking with more camping/hiking gear, heading out in “bad” (wet/windy/etc.) weather…or all of these in combination - I find that the logistics of using a cascade case can often be troublesome…and at times like these it would be much simpler/quicker to simply have a vertically-hung film holder case on a shoulder strap, with the holders themselves being equally accessible from the top.

As mentioned, I’d like this to be a hard case, which would, for example, allow it to be quickly crammed into a backpack with other stuff…hard and soft - and sometimes wet, when I’m above tree line and a storm quickly arrives. In other words, there are situations which do not allow for the luxury of time to place a soft case (even a padded one) into a backpack with the care that this often requires. Furthermore…there are times when I’ve been out with my Cascade case, working close to surf spray and/or encroaching rain…and the entire case gets wet and needs to be folded up this way. Also, being a fabric case, it can be a bit difficult to wipe dry in the field. A hard case can be quickly closed and wiped off - or simply shoulder-carried wet if need be while keeping its contents dry…assuming that it features a gasketed top.

Sorry to be so long-winded!