I know this was an old thread...
I recently did a slightly different version of this. I wanted whitewalls for my Dyno Roadster, and I had a free Huffy beach cruiser out back that had a set. The only problem is they had too much of a square-shouldered look, and were too knobby. On the rear it's fine but up front it looked like mud tires on a Cadillac.
I took a grinder, then a sander to the front one but I didn't take it all the way down to a "slick", I just took the square shoulders off and gave it a nice round profile. It looks way better!