Graphic Art Based on a Black and White Photocopy

Obverse Design First line is "CAR". Second line is "SHOP".
Reverse Design Only legend is the number "45".
Metal Brass Size and Shape Round about 33 mm in diameter. Small round hole on the left side of the obverse. Large irregular hole on the right side of obverse, probably damage to the example piece.
Dates Issued Unknown. Attributed to pre-1920's by seller Tom Crogan.
Issurer Attributed by seller Tom Crogan to the Panama Canal Company or the Isthmian Canal Commission's repair shops at Empire or Gorgona. During the construction days at Gorgona there was the "Car Shop" or "Car Repair Shop" where train cars (not automobiles) were repaired, so this may be a tool check from that shop.
Numbers Issued Pieces in collector hands include #45.
Rarity Very Rare. Manufacturer Unknown. Source Plumer Collection since 1975 Crogan sale.
Varieties None known.
Function This may have been a tool check. 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 #45 - Warren Lloyd Plumer Collection (simulated above).