To claim BTG you can just use Electrum Gold, electrumgold(dot)org/
It's the same as electrum, but for BTG instead of bitcoin
Stop advertising a scam site here! This wallet is not even listed in bitcoin gold's official site:
https://bitcoingold.org and it's not open source
Upon checking, This has been flagged as "malware" by electrum
Be extremely careful with altcoin versions of Electrum. For example, Electrum Gold is confirmed malware.