This "seed" is not reduced. That is why MyMonero shows a different address.
You can see the difference by looking at
https://xmr.llcoins.net/addresstests.html -- put the 64 hex chars in box 2. then click the button "Gen 3. and 4." Note the spendkey is not the same. To make MyMonero show the same address, just copy the new spendkey back to box 2, then press "Gen 1."
Thanks for reply Luigi... very cool. And thanks again for everything you do for XMR and all of us.
So, here's a copy-paste of what I wrote on the Reddit post about this recently too, just for future reference & posterity etc...
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OK just to make a summary here on the reddit thread for other people too, here's one way I've been playing around with this myself (have not yet actually put my coin together either, just getting familiar with all the process still...)
Using the cool tool from Luigi1111,
https://xmr.llcoins.net/addresstests.html Generate a new Monero address... hit all the "gen" buttons there to fill in all fields.
Use the site offline for security if at all possible!
Copy the hexadecimal seed there from Box 2 Either on Unix commandline (as per MoneroMooo info) or on a site like here,
http://tomeko.net/online_tools/hex_to_base64.php?lang=enPaste and convert hex seed text to Base64
This is what you PRINT and cut out on paper to embed into the coin under hologram
Test converting this Base64 text string BACK to hexadecimal on a site like here,
http://kjur.github.io/jsjws/tool_b64udec.htmlTest taking that hex seed back to Luigi's site and re-regenerate all the correct Monero address and seed words etc... to be sure your distilled-down simple short Base64 string that will be secure inside the coin IS able to be used to bring you back to your XMR access.
IF/WHEN everything seems okay, generate the info, embed into coin, send XMR to that address and be sure to DELETE EVERYTHING so that the ONLY record of that XMR is secure saved embedded into the coin.
Here's a quick example of doing all this start to finish... note I'm not gonna put any XMR on this address obviously so anyone thinking to try and use this to steal my funds, nope. Ha ha.
Mnemonic Seed Words:
turnip dwarf beware rafts shelter honked utility pact nuisance iceberg vitals match examine motherly oxygen muppet inwardly utmost cogs uptight twofold union flying furnished motherly
Monero Address:
43BZy5FRqYXMy4GaSd5HCEFS1jRQEx2v2PYb3MnA2sn9ABYYjx8wiYdZaThAZJWUVq2kWus4meTJoBh
1Bd7gxA2JLMM5JdT
Hexadecimal Seed:
921a3fe16d0d639eac835ff4251760942ebc6b168565c87fcbf66bf908e80004
Base64 Reduction To:
kho/4W0NY56sg1/0JRdglC68axaFZch/y/Zr+QjoAAQ=
Good Luck!!