Hey Upchuck
What you have (most likely) is the 414th frame produced in 1989. The F indicates that it is a Fat Chance model (not a Wicked, Yo, or Team frame). I'm not exactly sure when we started adding the model designator to the serial number. It could have been in 1989. I believe we were still doing overall production numbers for serial numbers then. We did switch numbering schemes - probably in 1990 - to indicate the number of a particular model produced.
I have an 18" Wicked that I built in 1987. I waited for 87777 to come up in the production run and then I grabbed that BB shell and kept it until I was ready to build my frame. The is no model designator on the 1987 serial numbers.
I know it is confusing since there were several serial numbering methods used during the Somerville years. I know all of the serial numbers were recorded in a notebook - mostly likely more than just one. If anyone knows what may have happened to that (those) notebook(s), then the serial number mysteries could be cleared up. I am not sure who may have them or if they even still exist at all. I don't know if Chris or Wendyll ever recorded the serial numbers on a computer to have those lists as a back-up.
Reggie Jackson was the keeper and assigner of serial numbers when the frames were first tack welded together. He was responsible for tracking those numbers. I believe Lloyd Graves assumed that duty after Reg moved to an office position. I heard that Reggie moved to California after he was let go but I have lost contact with everyone who worked in Somerville at this point.
Hope this sheds a bit of light for you
Scott "I-ROBOT" Bengtson Chief Welder Fat City Somerville 1986 - 1994