mmm45 - does the qualifying date mean the date they went to wherever, in this case France?
There is usually a one day difference between the date 1914-1918.net have a battalion landing and the qualifying date. As the latter is the date they sailed from England. This goes back to the 19th century when time at sea was included in Overseas service. As (for both) they reduced the pay as they were given food at sea and when overseas.
A interesting project for someone would be to see if a man sent to Egypt before the end of 1915, but landed after 1st January 1916 received the 1914-15 Star. If not then the one day difference only applied to F&F.
So it looks as it he was in the 13th Battalion.
I too think it will be for return of medals. It seems strange that a man deserted and then they give him a SWB. But di not give him his BWM.
On the card CRV = Certified Receipt Voucher, plus a date when the medal office receiving the medal back. It is hard to say if it was re-issued, as you would then expect a IV (Issue Voucher) reference and date.
Ken