Looks to me lime a bunch of extra shit nobody needs. You can get a stamping kit and washers at a hardware store, bonus, theres no clear motive attached to doing so.
The best 3d-printed Seed Phrase Stamper is now available in the shop. 
Inspired by the Blockmit Jig, this genius design features a screw mechanism which tightens a clamp that holds the washer in place so it doesn't move around when stamping. 
An M10 nut in the bottom serves as a mini-anvil, so you just need to place it on a sturdy surface and you're ready to stamp. 
This wasn't designed by me, but I literally couldn't have done it any better. Credit for the design goes to our friend who goes by the name MlePh, who isn't on nostr yet (speak out if you are) and this product is proudly being sold by us with his permission.
You can find it here: https://www.gobrrr.me/product/seed-phrase-stamper-m8/
It's perfect in combination with our Chrome Vanadium Letter Stamps too 😀
https://www.gobrrr.me/product/letterstamps/
...and our 3D-printed sealable Backup Bin
Discussion
Been there, bad quality stamps drenched in machine oil which break at the third hit. Fun 🤣