Some modern TPOs

I don't collect TPOs - Travelling Post Offices - but here are a few that I've found, all philatelic, starting with an envelope posted on a TPO in 1965 without paying the 1d late fee.

The next cover is from 1987 and went on the Great Western Down Bag Tender, with the cancel applied by arrangement.

The final covers all relate to the last Penzance-Bristol and Bristol-Penzance TPO in January 2004.