Those are pretty nice. I might have an original one...Ill post it if I do and send you a P.M. I know I have several 273's but I have an older 340 x head in the barn that may have them. I would have used a resistance spot welder rather than the rivets. But, now that you have them maybe drill out the rivets and tig weld the holes shut. That is a much better price they should sell well. Thanks for posting.