Old Time Radio Engineers

[ppppenguin]

....but that then means at full scale deflection, the 900 Ohm resistor is taking the remaining current.

I think you mean remaining voltage. The same current is flowing though the resistor and the meter.

There's something very odd going on here. A 5mA meter might typically have a resistance of 50 ohms. Hence 0.005V*50ohms = 0.25V across it for full scale deflection.

To make this 5mA meter into a 50V FSD voltmeter we need a total resistance of: 50V/0.005A = 10000 ohms. Deduct the 50 ohms of the meter and you get 9950 ohms. Unless you're making something very accurate you can forget about the meter's 50 ohms here.