Graphic Art Based on a Black and White Photocopy

Obverse Design First line says "TOOL". Second line says "CHECK". Last line is the number "659".
Reverse Design Blank.
Metal Brass Size and Shape Diamond (or square oriented diagonally) 38 mm high by 38mm wide (30mm from flat side to flat side). Round hole at the top. Corners are clipped.
Dates Issued Unknown. Attributed to pre-1920's by seller.
Issurer Attributed by seller to the Panama Canal Company or the Isthmian Canal Commission's repair shops at Empire or Gorgona.
Numbers Issued Pieces in collector hands include #659.
Rarity Very Rare. Manufacturer Unknown. Source Plumer Collection.
Varieties None known.
Function Tool checks were used to control access to tools. The worker would turn in the tool check in exchange for a tool. If the tool was not returned, management would know which employee had checked it out based on the number. I would appreciate e-mail from anyone who can add anything to the history of this piece.
Population Count Known specimens are as follows:
  1. Check #659 - Warren Lloyd Plumer Collection (simulated above).