When we got our first wood stove, I saw several places on very busy roads, with massive piles of firewood (leña), apparently for sale, unattended, and no way to contact the seller. Surely they would paint a phone number on the wall, at least?
After a few years here, despite some excellently run local businesses, the simple act of procuring materials often seems like a game of “catch me if you can.” Still, I think might suggest a sign if I meet the owner:
LOL. Show up with a big camion, start loading the truck. You'll find the dueño real quick.