Obverse Design All lettering is incused. First line in larger letters "I.C.C.". Second line, third and fourth lines in smaller letters "ENGINEERING &" / "CONSTRUCTION" / "DEPARTMENT". Fifth line with employee number in larger numbers ("16414" in the example above).
Reverse Design Blank.
Metal Brass Size and Shape Diamond shape with sharp corners. 40 mm wide by 65 mm high. Round hole at the top.
Dates Issued Unknown. These may have been id checks locally made and issued before the Diamond shaped Isthmian Canal Commission checks (which were issued starting in August 1905), or they may have been tool checks issued anytime between 1904 and 1914.
Issurer Isthmian Canal Commission, Engineering and Construction Department.
Numbers Issued Pieces include #150, #16414, #16907, #18824, #19990 and #24950.
Rarity Scarce. Manufacturer Unknown, but perhaps locally made. Other Catalog Numbers Asociación Numismático's ID-3, Hamlin's ICC-40, Rulau's CZ A74.
Varieties Known in brass and aluminum. Some checks have one or two additional small holes. If the lettering and numbers are undamaged, there is no reduction in value for these holes.

These may have been early employee id checks, before the general issuing of metal checks in August, 1905. They may also have been tool checks, or even used to track other equipment. I would appreciate e-mail from anyone who can add anything to the history of these metal checks.

Population Count Six specimens of this variety of metal check in collector hands are known to me. Recent sales include:
  • Check #19990 - Auction sale on ebay on February 6, 2007 for $47.01 in corroded condition.
  • Check #24950 - Auction sale on ebay on February 6, 2007 for $191.31 in VF condition.
  • Check #16414 - Auction sale on ebay on March 2, 2003 for $103.50.

Another Example of CK-1.1
Picture of another CK-1.1
Scale: 4 pixels equals one millimeter