It doesn't appear to have a Greener crossbolt so there must be something else awry with the toplever Purdey underlug mechanism. The overall shape of the receiver & the stock combined with the term "Sons" pretty much rules out Germanic in my book. It could however be a Belgian sourced longarm but it looks British. What type forend does it have and what is the difficulty in reading the top rib: Gothic script or something of the like? Also is there a Cockerill steel stamp anywhere? With the posted images, I wouldn't have divulged I knew anything about photography.
Kind Regards,
Raimey
rse
