Circa 1908-09 - never shown in any catalog, it was listed in the price list for 1909. The example above appears to be an early version with full hatched frame, these cars never had brake wheels  The car below would be later with its plain frame, cream tank with butterscotch detail, red tank top. 

Another Cream tank with brown contrast, dk green frame and a black top

End view of above 66 Tank, all the tanks on this page have similar ends as pictured above. This is for comparison to later tank cars.

Similar to above but darker yellow litho and green tank dome with gold painted ends.

"With the exception of the tank car, all "Princess"  freight cars we have seen have the same couplers as the passenger cars. If you look closely at the frame of this one you can see slots out near the edges to mount a passenger or other freight body. The other tanks we have seen don't have these slots. It looks as though they ran out of tank frames at one time and just grabbed passenger car frames, complete with couplers, to get some tanks out the door. All the other tanks we have seen have either the thin 1908 "Brooklyn" style coupler or the beefier 1909 "Brooklyn" style coupler, mounted out near the of the frame end so it will not interfere with the tank end plate which hangs down through the frame"..Rod Cornell

The above example shows the early tank with the small hooks, just like those found on the Brooklyn Cars from that year