This whole timing cover fits a 360 along with 273/318/340 is all new to me. Maybe they assume you just put a thick bead of RTV in there and throw the end gaskets away? Or maybe we should feel lucky a new part is available in the first place?
Anyone smarter than a box of rocks can make pattern off of a good or 'repaired' cover & cast an exact replica, that means they changed it on purpose, or they laser scanned it to make the pattern & something was off in the transfer.