Question for Gourou plane - Why some plane have missing instruments

[Rhubard]

There is a logical answer to that, but I'm wondering what was the main idea behind it.
I notice that it is more frequent with german airplane, looking at ww2 photograph. Was it for cost reducing measure, or some instruments required more time to produce and were randomly distributed to aircraft toward the end of the war?

I just buy the Me-109G6 and La-5FN and could not help but say, what and ugly hole it does in the instrument panel.

[Feathered_IV]

12 minutes ago, Rhubard said:

I notice that it is more frequent with german airplane,

 

Moral compass?