Thanks Daniel.
Currently I have 39 WW2 aircraft built, and 12 in boxes waiting. Then I will probably have at least another 20 WW2 aircraft to be close to representing around 75-80% of the aircraft during the period. I started with fighter aircraft only, then dive bombers were included and now I will start adding bombers. I also have some duplicates of some aircraft, but obviously with different paint schemes.
On the WW1 aircraft I have 5 built and 4 in boxes waiting. There were obviously significantly less aircraft in that period. So I can’t say for sure how many more I would need to complete those or even what the availability is in 1/72 scale? I do look occasionally to see what’s out there.
On the fighter jets, well that would also be a very big collection! I currently only have 8 fighter jets and would probably end up with at the very least another 20-30 just to represent the US variants.
So, my current total for all 1/72 scale aircraft built is 52. I could see that doubling easily in the future.

As far as display area goes, it seems aircraft became increasingly larger over the years.
See images below…
View attachment 526948View attachment 526949
I can fit around 12-16 WW1 aircraft per shelf. I can fit about 9 WW2 aircraft per shelf (fighters and dive bombers). Bombers will use a lot more shelf space.
And the fighter jets are at around 5-6 per shelf.