Yep looks like a lame attempt for a scam, mention signed message to prove ownership and you never hear from then again.
If OP dosen't reply someone on DF trust should neg rate him so he can't scam in the future.
I think we will probably see OP now post with sig to get ROI since his 1st idea didn't work.
Edit: Unless that fool moneyproofs finds this thread then OP will probably get the full loan and maybe more.

Moneyproofs is just lending to himself