By brainwallet do you mean a secure 12-or-24 word phrase? Or actually the incredibly risky and insecure method of deriving a Bitcoin private key from a short memorable string? Many brainwallets (like movie quotes, song lyrics, even complete sections of the US Constitution) have already been swept by attackers, and even more brainwallet addresses are being constantly monitored by bots that will sweep funds as soon as the address is used.
How did you generate your bitcoin address a few years ago? Is that software still available? You might be able to use it to sweep the funds to an address generated securely by your Trezor.
I have a brainwallet sweeper tool I use for fun low-value demonstrations, with lots of warnings about security:
You should audit the code before using if you can, but this webpage will search the blockchain for any brainwallet and if there are UTXO available, allow you to sign a new TX and sweep the funds to an address you provide.
As for the fork-coins, you may need to seek out resources in those communities separately, maybe someone can fork the code I used above and reconfigure it for other blockchains.