The PZ, #9900, has a larger front grill that has a slight "tear drop" look to it9901 and 9902 the Twin, above the windows. The layout of the windows on the original 3 car consist are slightly different than the other Zephyrs of this series.
Pioneer Zephyr was the first. Followed by 9901 and 9902 the Twin City Zephyr (TCZ) which had grills above the cab windows that were more straight. Injun Joe, 9903 was a close match to the TCZ. But the seating arrangement and windows, ROP and baggage section were all slightly different.
These 4 were the only completely articulated sets that the Burlington purchased - the power unit was part of the articulated cars.
After these 4, the Burlington then invested in class EA's in which the power units were separate from the rest of the passenger cars. However, the early passenger consists were articulated.
If you want to see the differences between the PZ, TCZ and Injun Joe, best to google them. I have many books on the Burlington, but can not post photos unless I am the original owner of the photo.
RAY
