Now that my new DC is built, wired and in place, i measured out all my ductwork and put in order in to my local HVAC and woke up to it already dropped off by my garage. Three fittings, including the one that is my starter fitting off the DC is being transferred to my local location from one of there other locations so those might not show up till tomorrow - I hope. That will give me the a new years even/day project.
All my parts are 26g smoke pipe, and the nice thing about smoke pipe / flue pipe wye's is the air flow is expected to go from multiple sources into a chimney stack, so the crimp side of the fitting is oriented correctly for the air-flow going from the machine to the DC.