The first is a pair of FWDs.
The second, is indeed a Thornycroft. It has a body by Dennis Brothers of Silchester Street, Notting Hill, London, who were known for making horse ambulances. The patent can be found here: https://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&II=0&ND=3&adjacent=true&locale=en_EP&FT=D&date=19171029&CC=GB&NR=110782A&KC=A#
I've some more photos of this contraption, which I'll post later (unless someone beats me to it).