19 April 1946 Folded brochure printed "PER BOOK POST" franked with 1947 1/4a greenish-blue pin-perf on thick soft unsurfaced paper tied by two strikes of "KISHANGARH / RAJ POST / 19 MAR 46" cds. SG lists the date of issue as 1947, this cover most likely the earliest known usage and predates SG listing by nine months.
