Any Way to Date Swedish M39 Packs?

I picked these up the other day cheap. Doesn't seem to be any way to date them other than pre 1941 and post 1941. These two are both post 1941 as they have the three crowns instead of a single crown.

I thought maybe the fabric, rivets, type of straps, etc might be able to date them somewhat. Anyone know anything about them.

I would guess the tan one is the older of the two but that's just a guess. It has a pair of straps that were sewn into tubes.

https://www.milsurps.com/images/impo.../hGhyri3-1.jpg

https://www.milsurps.com/images/impo.../S3HjQYh-1.jpg

https://www.milsurps.com/images/impo.../uCeLLPD-1.jpg

https://www.milsurps.com/images/impo.../kN6oSe7-1.jpg

https://www.milsurps.com/images/impo.../OGGiy6j-1.jpg

https://www.milsurps.com/images/impo.../cTjJYlg-1.jpg