I noticed this thread when I was moving a load into more appropriate forums.
I have a period reference showing that Bann 451 existed in September 1938 but it definitely didn't exist in August 1937 so these straps must have been issued at the very end of the life of the pre-1938 pattern straps. With that in mind it is odd to see chain-stitch on these particular ones.
This is incidentally one of quite a few units I've noticed so far for which Saris gives conflicting dates (according to his
book this Bann is first noticed as being in existence in March 1939). It should be remembered that the dates he gives for the units are for when
he first sees them mentioned in his sources. They aren't always necessarily the
actual date when the units were raised.
My personal approach to these lists was that the only people who could compile them correctly and reliably were those who were employed during the period to do it. So what I do is to simply post transcripts of these period lists rather than reinventing the wheel by compiling them from many different sources today as Saris clearly did for sections of his.
Whatever, two different approaches gives the collector two different sets of data to do with as he pleases. We're all definitely in a far superior position than we were a few years ago that's for sure