274th - 283th Corinphila Auction - Day 4

1882: 25 st. blue and pale blue single franking on foreign return receipt from Constantinople, tied by a blue strike of the bilingual Tirnovo cds (Dec 2, 1888) and in excellent condition. The return is documented by the cyrillic strike of TIRNOVO dated 16. Dec. 1888 on the reverse. The postal rate for this additional service was 25 st. Return receipts abroad are very rare. Opinion Penev (2021).