My first Model IV-1200 was ordered in late 2002 from Denney, and delivered in March 2003 by Skystar. The numbering system changed with the change of ownership. My serial number was CCU-008. This refered to the third month of the third year of the decade and I think the 008 was the eighth kit delivered. My take on your number would put it as a Model IV-1200 produced in October of 1993 and the 104th kit produced. The U designates it as a long wing IV vs. the Speedster which had a S in the third letter location.
The Classic designation came after a short period when the IV was discontinued and then reintroduced with the Classic IV name. Chase is spot on regarding the serial numbers during the Denney years, and would designate the 1050 from the 1200 during that time. The numbering system then varied according to who owned the company and all numbers after the break Chase refers to would be the 1200 as well as any with the odd assortment of numbers that follow, as the 1050 was produced for only a short time ending in 1992. My present project was delivered in 1992 and holds the serial number 1746.