One of the tell-tale signs of the bottle washer is rings of scratches at the
shoulder and on the edge of the base. It comes from the metal gripping
mechanism in the washer -- anything that protrudes gets rubbed. The other
aspect of wear and tear is the type of vending machine they were installed
in. Even the earliest types (coolers with slots and a controlled removal
system -- slide the bottle down the slot etc.) leave distinctive marks on
the bottles. Trust me I've filled 'em all. For example, the old rotary
dispensers left scratches tracking vertically down the sides of the bottles.
And don't get me started on hand cleaning. I used to have pallets of bottles
from bingo parlors that had been used for ashtrays, wastebaskets, and worse.
It was an education.
John Dendy