Lets say I just bought most of a Dura-Ace 7700 9spd group for $130.

(no cassette, chain, or crankset)
But I also got a very light carbon 700c 18 spoke front wheel + tire for that price (Velomax Ascent).

Let's also say I have 2 bikes, and can't decide which one to throw these parts onto.

One - fits me damn near perfectly. 1980's KHS Competition 10-speed that I converted to 7 in the rear when I replaced the freewheel. It currently has bar-end shifters, suntour cyclone derailleur's (super light), sugina mighty double crankset, and crappy 27" alloy wheel/tire in the front, and a crappy 700x35c reflective Michelin city tire setup in the back.

The other, a 1985 Centurion Ironman that is completely original, dark metallic grey paint, full shimano 600 group set in perfect condition, downtube shifters, 700c wheels with 600 hubs, etc.

The KHS is 68cm, and the Ironman is 62cm. I'm 6'5".

I ride the KHS everyday to work, the Ironman I just use on the weekends if I go on a longer ride as it's a much faster and lighter bike, and the skinnier tires on it are more prone to flats which would make me late for work.

I have a feeling that throwing these DA parts at the KHS will transform it.

Would I hurt the value of the ironman by swapping out it's original 600 parts for more modern DA?

I would have to find a rear wheel, spread the frame, and buy a cassette/crankset to get the full use out of this groupset on either bike I imagine, right? Both my bikes right now have 7spd freewheels. I would also need some cable stops for the ironman to change from downtube shift.

Would I be able to use all of the current 7spd gears if I just slapped these shifters onto either bike?