Lithographed Roof - most of these early caboose's have painted roofs. The Litho roof doesn't appear to be related to date as the one above is 1912 and the two below are 1910-11.

Circa 1910-11 - Blue roof with all white cupola, T Trucks, non-embossed frame, hook couplers.

Above is Circa 1911, below Circa 1912, lots of different colorations to roof and cupola. At least one example we've seen had a lithographed roof.