why is the label Trim R Rudder upside down?
I didn't notice I unwrapped it in the fully turned position. So it should be inverted, for sure. The indicator itself shows that it's not turned yet.
I bet you would be able to fly the aircraft by reading all labels alone
One may have noticed there are two levers for throttle (GAS), two for propeller (PROPELLER VERSTELLING) but only one for mixture (H.GAS*). The mix control for both engines is controlled by one lever, the blue one. It has two positions: normal and lean, and is automatically regulated.
You can see a doornkob lever at the left console. This is the throttle friction.
The main power switch, red and denoted as HOOFDSCHAKELAAR, has two positions (well...), IN and UIT, which is IN and OUT... The label is red, probably because of its importance. In Crash museum, close to Schiphol here, there are remains of the D.21 (big wreck) and of two T.5s (small pieces). A label in the D.21 showcase said: 'TKOPPELE' 'UURBEWE', which would say: ontkoppelen stuurbeweging, or unlock flight controls. Seen here next to the carburetor instruction plate of the D.21.
I couldn't locate this label in the D.21 cockpit, and the D.21 doesn't have a functionality like this. Until I read through the T.5 manual, where the second pilot/top gunner could 'ungear' the first pilot's flight controls from the system to have full control. Same kind of red label. Here we see it in real:
Cheers!
* H.GAS is an abbreviation for "hoogtegas", which literally means "altitude throttle". As altitude increases, air density decreases, but the fuel-air-mixture should remain the optimum yet. So it's the throttle for altitude

I sometimes have difficulties in linking the Dutch prewar nomenclature to the modern nomenclature.