Alan, I don't believe the bottom example was ever an MOD purchase, it has no acceptance marks or NSN to link it to the L42. The no4 conversion has the obvious alterations to accommodate the L42 rifle and its has the standard ww2 marks you would expect to see, dated 1942 in this case. The second example was a purpose made soft case for the L42 bearing the NSN as listed in the illustrated parts catalogue and CES. My point to some degree is to illustrate the two known and accepted carry cases for the L42 sniper rifle and to also illustrate the "Trojan" that is regularly passed off as "an L42 slip". The green example of the same pattern partly being to blame for the confusion. I think if the MOD had purchased these US manufactured carry cases they would have at the very least the crows foot arrow denoting MOD acceptance.
The US case has a three bar type buckle however it is attached to the strap by an outer bar allowing the fastening to be done in a reverse fashion opposed to the strap being attached to the centre bar allowing the strap to fasten in the traditional way. (hope that makes sense).