Hey Frans (
@Frans.Hendrik), I think there is a bug in your editor. I don't know if you are still working on it but in either case, this could be useful!
Your editor links to the sixth byte after the start of a kit and claims that this is the strip number. But I noticed that you should rather refer to the fourth byte. More often than not, the sixth byte's 16-bit value is 345, which is not the strip number since this problem repeats over a lot of kits.

And indeed, I think 345 is none other than the back number.

If you verify it in Hex Editor, you'll find that the sixth byte consistently gives you the corresponding back number.
Here is an example, but I am pretty sure this stands true for any other kit:

The start here is D1. Four characters later (01), we indeed find that NZ's away jersey corresponds to the strip number 01:

The sixth byte, though, gives us:

Opening strp_dec_101.pssg, we find that this is indeed the expected back number for that jersey:
