The teardrop shape of the flowers, and the way the leaves are made by "pulling" ("festooning") down from the flowers, and the little aventurine "bowties" say Czech for me.

I think there are a lot of beads like these that we are quick to say are Venetian, while they can just as well be Czech. Could be the same for these.
Personally, I have seen quite of few of the Czech beads made in a similar style, but most of those were newer. So I find it difficult to compare them in detail to Venetian ones.
Below is an image from the Jablonec museum, showing beads from a maker that could easily have made these too.
However, at the Sick & Co cards, on the pages showing all Venetian beads, are also beads with the pulled down leaves and flower, and the aventurine bowties. But no exact match.

I have a similar strand and feel that these are post-war Czech beads for several reasons including the fact that the design is entirely applied onto the bead. My beads are purple, which is more of a post-war color too. My necklace appears to have the original clasp and bead caps. The clasp is a fish hook into a 60's looking box. My genuinely old Venetians in this style have the flower directly on the surface of the bead, it is not raised. I attached pictures of the strand with other Czech beads and with early Venetian beads.

That is an interesting comparison. I do see the resemblance with your purple beads. However, there are plenty of Venetian beads that do have this type of raised flower and aventurine decoration on the Sick & Co cards from the 1920's.
I think it is time for a 'show and tell' of wedding cake beads, so we can connect some more dots.

Agreed! More examples are always useful! Should have included photos of the clasp on my strand that I used to date the strand. Caps appear similar to yours. Beads are about 5/8".

Here are the ones I restrung a couple of years ago, with original caps. At the time, Floor informed me of their likely Czech origin. The latticino had me thinking Venetian.