Cheers guys, some useful pointers there! Any idea what date it might be from the series nos.?

Having just watched some film on Squadron repairs to propeller blades the disc markings indicate covering, balance and type of wood. Repairs to blades are usually marked on the blade itself so not sure if that refers to the JP number? (JP may mean Joint Publication?)

Thanks Bob, that’s a line to pursue. Are there service records still available I wonder?