This terracotta-coloured plaque is supposedly now in Australia with one of the chimney pots. See Captain Cook's house for information and a photo of the house with plaque.
Our image comes from the Spitalfields Life article.
Site: Captain Cook’s house - E1 (2 memorials)
E1, Mile End Road, 88
The address was 7 Assembly Row when Cook and his family moved in, 1764.