I found a set of cast iron cars that look like some sort of crane car. They have a turret with a crank and a 8" high standard that the chain or rope went over and attached to the chain is a cast iron bucket or hook. The cars were unmarked except for a bird symbol by the coupler. The spacing on the wheels was around 2-1/4". The only reference to a bird logo that I found was MDC. These look to be late 1800's early 1900's. Any ideas?