[1][2] At the end of the Second World War, Willmot served with the rank of Major with the Monuments, Fine Arts, and Archives program (MFAA) as one of the so-called 'Monuments Men'.

[2] He worked on various aspects of the collection, including the redisplay of the Bird Gallery in 1951[1] and the Roman Gallery in 1958 (after a £350 grant from the Carnegie Trust,[4] and opened by Sir Ian Richmond), and research and improved storage of the important Geological 'type and figured' specimens.

[5] Academically, Willmot undertook important and pioneering work on Bronze Age beakers that was never fully published as well as directing numerous excavations of prehistoric sites in Britain and Ireland.

The results of these excavations were also never formally published and exist only as unpublished notes and short reviews.

[7][8] The excavations in the abbey utilised volunteer excavators drawn from the members of the Yorkshire Philosophical Society and students of Bootham School and extended beneath the abbey to include Pre-Norman and Roman levels.