There is a slight offset difference between the YH and FW 15" rims, but it is very subtle (about 1/2"), and does not affect tire clearance or brake clearance IMO. I have a set of FW's on my Z11 (YJ's are stored, reserved for show duty w/Goodyears if I ever get to that point), and work/sit right with the 205/50/15's Goodrich T/A's I put on it to drive. Like most RS cars, you have to watch tire size in width and diameter to keep from rubbing the actuator covers, but they work fine and look better to me than the 14" YJ rims in filling up the wheel wells.
When you install the derbys and rings, you'd be hard pressed to see a visual difference between the two. Off the car like these are, look at the center sections position compared to the rim on a known set of YH's and you can probably see the difference. As with everything nowdays, some people will try anything to make a buck, including restamping rims.