That they are both identified as "GF451" on the bags suggests they are the same. Maybe they just changed the case color. Have you gone back to the seller and asked them? Auto advance is really just important for starting and idling. Are you hand starting the engine? You could still use the ignition and couple an advance mechanically. If you paid by PayPal, you have recourse if you got the wrong thing and choose to return it. Like W8YE says, you shoulda, but still coulda, bought an RCEXL. Just my random thoughts on the issue, FWIW.

Regards, Richard