GR over P Barrel knox form or action body - George V cypher between 1910-1936
P - SMLE, left hand side of knox form - Replacement barrel?
/|\ - Broad Arrow, used from the mid 19th century to distinguish legitimate ordnance surplus stores.
'17 Firearm, on barrel knox form or rib - Production year, especially on replacement barrel.
The others I am sure will be deciphered by more knowledgeable folk I think the crows foot inside the D is sold out of service but I could be wrong on that one normally its an S with apposing arrows any way there is a little bit there.