Pupo, I would run away from that block while screaming if I were you. An copper bottom with exposed soldered on base fins and an unplatted alunimum top is nothing but a pink slip waiting to happen. If the owner is trying to sell it to you say "NO!", and if he is thinking about using it, grab it from him and throw it as far away as you can (think of it like a hand grenade as its just about as dangerous to the loop). That think will require a full anti-corrosion premix and regular cleaning to make sure nothing goes wrong. To much effort and pretty poor performance for a 3-4 year old block that was never able to compete with other blocks of the day.