yours will be easier to do then as i think the clock display will have filters and not the hard to find and install chip leds like my annie clocks have, and like richies had, all late clocks use the chip leds but the early spec clocks dont so you could be lucky a sit will be easy as hell to do
if i saw a pic of the rear of your clocks i could tell you for deff,
i can do any of them..but the later clocks are alot more complex and not for the faint hearted to try