We have some of those at our retail office. I'll ask how to set them.

Oh that would be wonderful Lori. Thank you so much!

Video on resetting or discerning the combinations:

https://www.youtube.com/watch?v=ag5-BZ1Dfe0

OK, I asked. I guess we have extra locks . When one needs changed there are two screws that you remove and slip in another. These just rotate around through the boxes so one lock could be PO Box 3 for years, someone new takes that box and another is pulled to replace it, the original put back in the case until it's turn comes up for being back in service in a different PO Box.

However if they are just locked and you need to open them reach in from the back and push the pin back toward the hinge side. You can now block the catch with a bit of wood putty or J B Weld (depending on how permanent you want to be.The doors will close but be unable to latch and lock.

Thanks so much to both of you. I will at least be able to open the locks with Lor's suggestion. Then with Sombreuil's suggested video I might be able to reset them. Could combine to work beautifully!

If I had those I would do very little if anything to make them look newer. If you decide to restore them look up a process known as electrolysis rust removal aka magic ,well maybe you can skip putting magic in the search title but it really is. The process is rather simple but the reason I don't explain it is because there are several versions that people like useing. The main variable is what is mixed with water. I've tried a few and found washing soda measurably out performs others. If you have difficulty finding washing soda,call or email Arm & Hammer for the distributor for your area. You will not lose any iron/steel but remove 99% of rust from every nook and cranny. Wire brushes can't get into all places and sand blasting eats away metal. I would clear coat with "FLAT" finish but whatever you choose have it bought and ready or the metal will just rust again very soon.

Judging by the verdigris/patina (and my own memories of the PO) they are solid bronze, not steel.

Casey

Thanks so much klem 1. I will try that. Casey- the front is either bronze, as you mentioned, or copper (my uncle says it is copper). The back and sides are the very rusted metal that klem1 is referring to. I had thought of leaving it as is, but the rust portions make it rather unfriendly to the sewing materials I hope to store in the back. I worried that sand blasting would eat the metal away and I wouldn't be left with much. Perhaps a clear coat of something matte to arrest the rust and stop the flaking while maintaining the very vintage look.

There are many forms of "sandblasting", these days called media blasting. The media can be many things from various kinds of sand, ground walnut shells, glass bead, and I sure more. Talk to someone that is an expert in this. Some of this different media is for delicate materials.

I have a friend that builds street rods, with finishes rivaling mirrors, and they use glass bead, it's gentler on the metal.

" Perhaps a clear coat of something matte to arrest the rust and stop the flaking while maintaining the very vintage look."

That's only true after rust has been totaly removed. On farthur consideration I'm thinking flat rust colored paint might be a better choice depending on appearance after rust has been removed. Clear will preserve and protect but color of metal might be unattractive following removal of rust. It's for that reason it might be wise to have both on hand then return unused product. You will of course achieve better result turning it over to a restoration expert as suggested by someone above but I naturally assumed you want to diy. I reccomended a diy friendly approace that yields pretty impressive results. There are indeed better methods but they require special training and expensive equipment. Perhaps you should reiterate your desire to do this yourself. It seams some just don't grasp the self satisfaction derived doing these things themselves instaed of buying/hireing everthing. I am the first to reccomend turning it over to pros if the chore might explode,make toxins,kill or maim the unsuspecting. Oh well,I'm sure most people recconize some free advice is worth exactly what they paid for it. LOL. Best of luck,you do have an interesting item in the boxes. Your sewing friends will be green with envy.

When I need to "restore" old iron hardware on an antiques, I first remove as much rust as I can, using anything that works, sand paper, steel wool, navel jelly, etc.. Then to give it a "patina" I use the stuff in a spray can that claims to change rust back to metal (?). Maybe it does, maybe it doesn't, but it does get rid of the rust color and make it look like old iron. Then a clear coat of satin. Sorry, I don't remember the name and I don't seem to have any here, must have used it up on the last project. I get it at an auto-body supply store. The chain auto stores may also have it (I don't shop at chains :) ).

" I don't remember the name"

Phosphoric acid (also known as orthophosphoric acid or phosphoric(V) acid is the active ingredient in most brands.

Thank you all so much for your guidance. Klem1, I do want to complete this job myself. It is a great opportunity to learn some new techniques (as long as I don't irreparably damage it in the process). It will also be much more satisfying to me when it sits in my home to know that it was my effort that went into it. Al Fortunato- We used to use a product we called Ospho on some of the fittings on my dad's commercial fishing boat. It must be the same thing. And if the project sits too long unfinished I will sure consider sending it your way. I know it would have a good home. Thanks so both of you!