Thank you for your help. I think it is just a signature. Very weierd, because he clearly states that he has sent bitcoin
I see 0 to mix PGP into this. Just ask him the TXID if he did send it. I'm assuming you sent him a BTC address and he is to send BTC to that address. No Bitcoin is going to go through PGP, you can't import it into your wallet, he has to sign and send from his wallet.
I very much doubt he would instead send you the privkey for you to access the BTC, so PGP has no place here.
The attached file looks like a signature. I guess it doesn`t have anything to do with btc. I must have missunderstood.