Ive never seen them with inserts like that... always straight vinyl. Maybe the PO had them redone or maybe Im wrong I dont know. They are in the same pattern as stock seats and even have the plastic inserts in the center.
Its a camping/table-top propane grill. I was told that was fine... just no bonfires or charcoal grilles. And if you keep being so negative, you wont get any delicious breakfast burritos *humph*
Too bad its not a 5bolt one... I have two of those, but only one 6bolt and I need it. Good luck as it took me a awhile to find one. They are out there though.
Yeah, Ive never seen the size or count of the spline on a 520/521 to know if they are the same as the 510. Im doing a bit of OEM+ theming to my 510 where a nice wheel like that would be perfect.