Less than 40 miles away from where it was posted, one would have thought that either the typist of the envelope or the workers in the Post Office would have heard of the village of Thorpe Waterville.
Instead the letter was sent to Waterville in Ireland.

Posted in Spalding : 1 FE 72.
Routed through London the next day.
Arrived in Waterville / An Coirean : 5 II 72. Also postmarked there : 6 II 72.
Then passed to Killarney / Cill Airne : 7 II 72.
Franked 'Undelivered for Reason Stated: Return to Sender'.

All that for 3p!

Standard size C6 envelope in white,162mm x 114mm.
It is clean and uncreased,