You haven't asked a question.
25 HUNDRED
Kits were made by Connecticut Valley Arms Otherwise known as CVA
It's a Derringer snake-eyes. I just spent 6 hours tracking it down and I can't find any with the CMC stamping, but that's what it is. Further back they were sold assembled and I suppose that's where they got the stamping, but now they're just sold as kits by different companies.
CMC powder is used in ice creams because it works like setter and gelitine.
50-100 or so
$50
check on line for CVS gun parts
CMC Electronics is a company, not a geographical location; therefore, it does not have a population. It is a Canadian electronics manufacturer specializing in aviation and defense industries.
While I haven't found an actual study about the degradation of CMC, Food Grade CMC is usually regarded with a shelf life of 2 years while dry. If your CMC is already dissolved in water it may only last a few days before algae form. CMC won't fermentate, so, unless it gets wet, if there's no trace of algae in the top it's not spoiled but may have a reduced performance after 2 years in storage for food grades and 4 years for industrial grades.
CMC Electronics was created in 1903.
CMC Markets was created in 1986.
CMC International ended in 2000.