Truck rim

Hi guys. These rims are currently fitted to My Thames Trader and it looks like original 50 year old tyres too.
What I find unusual is the 8 cutouts (or whatever they are called).
All other photos I can see of TT's have only 4 cutouts.

Rims with the 4 cutouts were possibly earlier type, and possibly lighter construction.
Just lookin at my terrier rims, with 4 cutouts, they are a lighter material than some others i have here , with 8 cutouts.
My guess would be that the material would be easier to press into shape with 8 sections over the 4 sections of lighter steel.

8 stud steel rims seem to come in many designs. I have some with 4 holes, some with six, some with 8 some of them are narrow and some are wider!

As a generalisation the multi cutouts were on older trucks, particularly rivited rims. At the time it was critical to tare under 3 ton (in pommyland), not just cheaper tax but you could do 30mph legally whereas over 3 ton was limited to 20mph, Every ounce of steel counted and I suspect weight saving is the reason. As time moved on cutouts were reduced to four and then two (for purpose to access valve on twin wheel) in heavier rims. Traders came in different weight capacities and each would have had a different tyre spec which could also account for the different rims.