Found from dipping in Washbrook (shallow stony brook) 5 July 2022. I think the first is a mayfly nymph but slimmer than Ecdyonurus venosus; the second has 6 pairs of gills but lacks the three tails.
Thanks for any help in id-ing,
The first one is probably Baetis rhodani - https://www.naturespot.org.uk/species/large-dark-olive-mayfly but needs microscopy to check. The other one probably is too but it is damaged.
Thank you! From the link I can see the similarity between the photo by David Nicholls and the first of the two from the Washbbrook.