Great job done, it is probably the safest wallet to keep at home. I have some questions if you don’t mind.
1) How long did you take to complete this project?
2) Did you test the durability of the wallet using fire and water?
1) My short guide is here
https://pinode.weebly.com/hardened-cold-storage.html but in steps it took...
* Create the vanity address and key with a Raspberry Pi, 2 days (unnecessary from a security point of view) but if you're interested
https://pinode.weebly.com/bitcoin-vanity-address.html* Paint metal card with nail polish and mark design into the polish 40mins
* Prep the etching solution and electrodes 15mins
* Etching 2 mins
* Cleanup of the finished card 30mins
* Total 2 hours with added messing about, second guessing, checking etc
(The design was marked with a cheap laser etcher but can also be done with a laser toner printer, heat transferred on with a household iron.)
2) Now it's getting colder here in the UK I'll be testing it in the fire soon. In theory it should be fine but I'll post the results here with pictures when I have them.
Was thinking about similar, already mentioned on the forum, but it's a bit different.
I was using the same kind of metal business card, but I would like to engrave the letters into it with a hand engraver tool. My initial thought was to punch in the letters like a dog tag, but there's not enough place to punch all the letters, because of the blending of the material, you can't condense the characters enough to fit. So I have already ordered the metal cards off from ebay, now I'm searching for a proper hand engraver.
My first thought was using letter stamps too. I ran into problems.
1) The stamps needed to be upper and lower case due to case sensitive keys and addresses.
2) Aluminium stamped well, but has a low melting point.
3) Metals that had a higher melting point are considerably harder than aluminium and did not stamp well at all, barely left an impression.
4) As I continued practicing with the aluminium it was very hard to stamp the many characters in neat straight lines. End result was very amateur.
If you're looking for a hand engraver and it gets to around £50 then I would instead recommend looking at getting the laser etcher I did. The laser etches wood, paper and most plastics. Then to etch metal and glass it can still do the marking out very neatly into nail polish, then apply glass etching gel or immerse into a chemical bath for metal as I did.