GS indicator circuit-Jim Weir?

This question is mainly aimed at Jim Weir, but others are more than welcome
to give their 2c.
With the aero-lectrics column in kitplanes, a GS tester has just been
completed.
My question. How hard would it be to make a GS indicator, with say LEDs
instead of lines and needles. For example, when going down the glideslide,
needles centred, you get a Green led in the centre, diverge and get yellow,
really off and get red, the universal warning. Rotary encoder with 7
segment leds for OBS. How hard would this project be? (considering the
grand scale of the test unit just completed). Obviously not for Primary
use, but as a tester for radios, and possibly a back-up unit.
Thanks.
Just a thought.
Rob
Australia.