Sad news about the day old commuter? what lock did you have on it? I wanna upgrade my daily commuter but scrared a good brand, shiny bits and non matt black paint will attract scummaz. :-s
The Karakorum I love, prob the sort of thing I'd like to buy if my GF didn't keep catching me bidding!
Definately in my opinion keep it retro. I'd stick with the rigid forks, a nice stem (what was wrong with original?) and only upgrade if ya must new tyres but I'm running retro tyres again saturday...
I gave up old bikes for new but got back into it. Easy when ya buying new (old) bikes but when its ya old en ya can easily take it for granted. If ya owt like me you'll get the bug. A few new bits and a retro bike ride, that should do it.
If ya wan't a scruffed up city bike one can be bought built pretty cheap, be decent and still not be that attractive...