I haven't welded them on yet, but I have done some very close comparisons and find the panels I have gotten from NPD are very close to the original panels...they certainly seem top quality.
Also, don't get discouraged if your questions don't get answered quickly. Sometimes it takes a little time for the person with the right knowledge to get logged on and respond, but most questions get answered the same day. Weekends are also usually very slow...everyone is at shows or wrenching...
If you go to the "My Home" tab at the top and set your viewing preferences for 99 posts your posts won't seem as lost.