Bitcoin Forum

A guy inherits 21 BTC as a collection of numerous legacy addresses on an obsolete USB hardware wallet with no screen. The wallet is no longer supported but still works with the original Windows software I/F. The coins are accessible. He also has the private key (not seed words) both in written form and as .pdf on microSD.

He wants to send the coins to a modern HW wallet to secure them properly asap. This will be for long-term cold storage, not for spending anytime soon.

Should he:
Move them on-chain (to Segwit or bech32 addresses)?
Lump sum transfer or send in smaller (what size) increments?
Restore the private key to a new HW wallet?
Spread over more than one new HW wallet? Which wallet/s?

Best practices in this scenario? Practical suggestions? Hints, tips, and pitfall warnings?
What would YOU do to best protect this Bitcoin?

He can do anything but I would suggest them to restore the wallet with the private key then have.

Use electrum. https://electrum.org/#download
Make sure you are verifying the downloaded file before installing it. Also use a new operating system after all 21 BTC is a lot of money and you do not want to take any risk.

Check this turotial: https://bitcoinelectrum.com/how-to-verify-your-electrum-download/

Do not install the file without verifying the signature.

I am watching the topic. Let me know if you need any help.

'He' might like to read and implement the Glacier Protocol - https://glacierprotocol.org

21BTC is quite a nice amount. I would build a cold storage from those private keys. Keep in mind that cold storage machine, after the point the private key(s) inserted, will have to NEVER ever go online.
Since the addresses are also available, he can set up watch only wallet(s) which will be used to see the funds, create transactions (that can be signed with the cold storage), broadcast transactions.

And of course, the smaller funds he wants to sell now and then can stay on newer (bech32) address(es), maybe tied to a hardware wallet.

I would not move funds from the original place if not necessary; as long as the private keys are safely stored offline, as long as the transactions are signed with an offline cold storage, the funds of "a guy inherits 21 BTC" should be safe.

For secure the coin, I will suggest you don't use any kind of protocol except electrum wallet or other reputable bitcoin wallet but there is no need to access the real wallet since he know the genuine private keys.
Download the electrum wallet as said by Royse777 verify it, sweep private keys (https://electrum.readthedocs.io/en/latest/faq.html#can-i-import-private-keys-from-other-bitcoin-clients), use Download Mycelium where you can easily import the private keys or Bitcoin core (https://en.bitcoin.it/wiki/Help:How_to_import_private_keys_in_Bitcoin_Core_0.7%2B).
However, he will need to claim his BCH, BSV etc.

I would buy 2 ledger nano.

Recover the seed in electrum wallet (the old private keys) and send them instantly to my new wallets in ledger nano  (10.5 btc to each). I would keep both seeds saved in a separate place.

The best is to buy a hardware wallet. Do no bothering making a offline wallet, offline computer and all that shit. Too many risks for a too high amount of money. Just pay a few USD in those HW wallet and let the professionals handle its security.

I would do the same although I wouldn't call offline computer risky. It's not hard to do when you have some experience with computers in general.

Using a hardware wallet is more noob friendly because they guyide you by the hend what to do and how.

Just to remind you that ransomware that encrypts files was found to be causing problems with hardware wallets by blocking your ability to access them on the compromised machine.