I have for several years known the above cutting, which was until recently in a distinguished south London private collection.
A sister cutting was in the collection of Neil Phillips, sold at Sotheby's, 2 December 1997, lot 64; it was not illustrated in the catalogue, but it had been reproduced in an exhibition catalogue of the Katonah Museum of Art, NY, Medieval Monsters: Dragons and fantastic Creatures (1995), no. 67:
The form of the hybrid figures, combined with the form of the initial itself with openwork interlace, and the maple-leaf foliage infill, are quite distinctive:
Knowing these two cuttings, I recognised two more a few years ago at the Lilly Library, Bloomington (Ricketts, F. 9):
EDIT, 21 Aug. 2021:François Avril kindly tells me that the ex-Neil Phillips cutting shown near the top of this post was resold at Piasa, Paris, 11 December 2014, lot 15: