6 Kreuzer Württemberg arms blue, horizontal pair on folded letter, good perforations all round, fresh colour and very good embossing, originally attached to letter, single-circle "HEILBRONN 11 NOV. 1865", correctly franked to Paris, 6 Kreuzer Postal Union rate and 6 Kreuzer onward postage, clear contrasting ancillary marks on reverse, perfect condition, unsigned, Klaus Irtenkauf BPP photo certificate (2020) "genuine and faultless...in fresh condition", ex Erivan Haub collection