If you have your private key, you can just use same key to trade forked coins (using given coin's wallet). If you don't I guess you depend on whoever has your key. But rule of thumb is, you don't own a key, you don't own a bitcoin.

I would just move original coins to different wallet first as I'm not sure if same transaction cannot be replayed on main bitcoin chain.

You can check here what you can get for your addresses https://btcdiv.com/