ChinaThailand 1924 Airmail envelope to Cambodia via Ubol
bearing 2 sat Brown SG147, 3 sat Green SG212, 5 sat Red SG214, and 25 sat Blue SG221, tied by Bangkok datestamp with instructional By Air Mail, with transit on reverse and Pakse and Pnom-Penh arrivals in Cambodia. Scarce. (pt)
