Item #: 32844
The signature looks like 'Harry'. The cap badge looks RAF - you might be able to read the initials in the centre on the original.
Relatives usually have some vague recollection regarding who served in what. Possibly identification could be made by asking? Is it likely that the photos came from a wartime collection of buddies?
The owner of the photographs has no idea who they are sadly. I have tried to see if any of the war photos are of the same men but I can't see any resemblance.
Cap badge looks to be Royal Engineers.