Great work Floor, you made my day with the sample card which shows the red spherical simulated painted chevron.
It is the first time I see this type on a card and I was really excited.
This bead is in our chevron book as # 488, 497 with a couple of other colors.
These were very rare even in the 70s, probably because they are hollow and fragile so only a few survived years of handling.
If the card is in the Jablonec Museum, there is a good chance that it is Czech.
Do you remember if that bead on the card is hollow?
Is the name on the card the maker, the customer or somebody else?