Penson continued to exhibit at the Royal Academy between 1856 and 1859. He was a leading early member of the Cambrian Archaeological Association and was elected a member of the Society of Antiquaries of London in 1853. Sometime after his retirement, possibly after 1871, he had moved to Plas Dinam House in Ludlow, Shropshire, where he died, aged 69, on 22 May 1885.
