So after consulting with ENY about this model year/build year dilemma - I've decided to go with model year exclusively for the depot roster. A fleet roster will be created to distinguish model and build years, as well as provide more in-depth information on the fleet as a whole. For now, the depot roster is updated - the information above that ENY posted is the internal roster information on the buses - the model year on the rosters is based solely on the spec sheets, which ENY clarified with me.
Thank you ENY for the help, and as stated - the depot roster is updated. When the fleet roster is finished, I'll post it up. The NJT and SCT rosters of course will be finished first. Some wacky stuff going on with the coding, hence the delay.
https://sites.google.com/site/nycbuses/home