That's a nice idea, with the airshots!
Regarding the 'openend', or opened: maybe 'established' is a better word.
And regarding the years, well Monza's first layout will be from 1922, 1950 had a somewhat different layout and so on. So 1922 may be correct, but not for the GTR2 layout. The same goes for Spa. I believe 1983 marked the departure of the long Spa, and the GTR2 versions are from 2003 and 2004.
I did some research on the 'years of opening' because I like my tracks to be period correct for GTL, GPL and P&G. It's NOT easy to get them all spot on, and my list is far from complete.
But don't get discouraged, maybe you just need to decide if you want to show the years of the initial layout, or the years of the layout the loading screen refers to and stick to those for the complete series of screens. If you then mention what the year refers to on every loading screen no-one will have anything to complain about or correct you on.