Mount Shamrock post office, 16 km north west of Biggenden, opened on 7 November 1886
- Datestamp type 3c (23 May 1887) rated 5R - $100
Awarded Large Vermeil at EuroPhilEx 2025. A handbook on Queensland colonial post office datestamps and instructional markings by Dr Jeremy Hodes. To find the date stamp you are looking for select from the alphabetical tabs directly below.