Any help how to get access to a wallet using the backup keystores from the "old"/"classic" wallet?
Do you mean the vintage one? I also use vintage MEW. But now, Vintage MEW has migrated to MEW (new MEW) since 20 October 2019
First, do you still have the private key? Or only saving the Keystore?
From what I have read on the
https://kb.myetherwallet.com/en/migration/importing-vintagemew-to-mew/Here you are able to access the same wallet you used on the Vintage version of our site, through the same method.
There you can also find the completed information about Vintage MEW migration to the new one.
Go to "
https://www.myetherwallet.com/access-my-wallet"
here, you need to find this menu and there are some options to choose to access your wallet.
To use the keystores, it is said "Not Recommended" because:
NOT RECOMMENDED
This is not a recommended way to access your wallet. Due to the sensitivity of the information involved, these options should only be used in offline settings by experienced users.
However, as I remind is that in the vintage MEW, it is also not recommended to use PK, Keywstores, or other software in accessing the MEW. They more suggest us to use the "Offline wallet" or other three options above.
Not recommended doesn't mean that you cannot access the wallet. You can still access it, but it is on your risk because it may be risky of hack or other. But so far, I personally use this way to access my MEW, access by software (mostly using Private Key or "Keystore+password")
The way to access even your vintage wallet is by importing your Keystore and then continued by entering your "Password". After accessing your wallet, I will suggest you import the "Private Key". For, this can be easily used to access your ERC20 wallet from other platforms such as Metamask and others. Here, save your PK securely.
But, if you want to access your wallet more securely, you can use the other ways as I attached above, it can be using MEWconnect Protocol, Access by Hardware, and Access via MetaMask. I think that Access via MetaMask is the easiest way so far I do, of course I have the private key to access on Metamask easier.
Actually, there is also a MEW application on Google Store and App Store so that you can also use this.
Sources:
https://kb.myetherwallet.com/en/migration/importing-vintagemew-to-mew/https://www.myetherwallet.com/access-my-wallet