From the sounds of it you won't be using it in bad weather, so I'd strip it right down of any surplus parts (apart from the kick stand) and chuck the fattest black tyres you can on it. Also see if you can find an old black brooks saddle and maybe a black mtb-style stem that angles upwards to follow the line of the top tube. Keep the bars and levers.
Then depending on what the wheels are like (are they steal?) I'd switch them for some velocity dyad's on some new hubs.
I think edmundro's got a point.
But if you are set on changing it....
From the sounds of it you won't be using it in bad weather, so I'd strip it right down of any surplus parts (apart from the kick stand) and chuck the fattest black tyres you can on it. Also see if you can find an old black brooks saddle and maybe a black mtb-style stem that angles upwards to follow the line of the top tube. Keep the bars and levers.
Then depending on what the wheels are like (are they steal?) I'd switch them for some velocity dyad's on some new hubs.
Just my 2p.