I have some old wallets from multibit era (~2013). There is no way I can now download the full blockchain, so I need to import these keys into somewhere. Worse still, I also need to import the same keys for BCC and BTG.
Try as I might, I can't seem to find clients that allow me to import old base58 keys. I have a few files called
something.key which came from multibit and are human readable with the private key in. Everything seems to be "mobile" and "QR codes", "passphrases" and whatnot.
It's not a lot of money, and fragmented over multiple wallets, so with transaction costs stupidly high now, sweeping is infeasible.
How can I spend these old coins? Is the only way to free up 150GB and wait?
Edit: Ultimately I just want to create a transaction from all these wallets, to send the coins to an exchange. So sweeping to a new wallet just doubles all my transaction costs for no reason. Also I need a way to repeat the process for Bitcoin Cash and Gold...
Is there no simple tool to just "create" a transaction?