wheel balance

[insane1400]

When I bought my bike about 4 months ago I noticed that there was a LOT of wheel weights on the rear wheel, 120g to be exact. The wheel had no signs of damage so I thought it must be a dodgey tyre or something (the tyres were 7 years old). Anyway today I was painting my wheels and I noticed something that I find strange, perhaps when suzuki machined my wheel it was a Friday after lunch... if you look at the pic, the "lip" closest to the spoke is nearly non-existant but gets bigger as it goes around the rim to the other side.
its not something you would really notice untill you have sat looking at your rim for an hour... anyone else seen anything like this?

[froudy]

I would say that a previous owner has had the rims smoothed down to get rid of the ridge in the middle.