The stenciling really makes the crates. A little flat & a little weathering,and they'll be ready for transport. I recognize many of the symbols that you downloaded, but what's the oval one above the "Vorsicht Nicht Offen"? And the circular ones on the sheets?
Well, the answer is: it depends. Many vocational trucks have spokes, but not all. Spokes were very popular in the Northeast (and still are). Sometimes you'll see a combination on older trucks: disks on the front with spokes on the rear. Many fleets in the 1960s & 70s ran spokes. Spokes are also very popular in Australia. So, like I said, it just sort of depends.
What I find amusing is that 1/25 scale cars (based on metric) are popular in the US, while 1/24 scale cars (based on Imperial units) are popular in Europe. Or at least it seems that way.