These are 6 glass half plate negs that were being used as supports in a recent batch of plate holders I’d bought. They had been described as 5×7 but turned out to be only half plate, shame really as some were in near mint condition.
Three holders held these six plates, they had black card glued to their emulsion surface which was easy enough to peel off mostly. A quick scan and here they are. I do like old images of everyday life, little details in shop windows, what people are wearing etc.
The image of the bus led me to this website – Early National Bus Companies The first bus at the top of that webpage is the same bus!