I may be wrong, but I don't think there is a discernable time when either Fred or Tad made the cues. From what I understand Fred mostly assembled and turned cues, leaving the point and butt sleeve work to Tad with Suzie doing the tip/ferrule installation.
It's more like a collaboration of efforts, I don't know the exact date that Fred started being a more active part of the cue making. I know for a certain time he just worked there on and off part time, then switched to full time but I couldn't tell you when it happened.