Hi there,... You have an interesting gun, but if it's blue it's a MK IV, not a MK VI. Both the MK VI and MKVII series were stainless. Your gun would have been made special for Alexander for it to have a blue "MK VII style slide". Such special made guns were not unheard of. Sometimes such guns were made to pay off a debt, say, to a vendor of parts or services. Sometimes they were done for employees, or friends of employees. A serial number, such as C21xxx, could reveal more about when the gun was made.

Deeton