Me neither
I also only received 210 of the AD-41H rivets. I emailed Van's and was told that yes, there were "some hardware shortages" and that they would be sending out more hardware, though there was no time frame given.
I got tired of waiting and ordered the AK-42H rivets from Wick's and the AD-43H rivets from Aircraft Spruce. Neither one had both types of rivets. It cost a lot for shipping, but at least I can finish the tank this weekend, well, except for the filler neck that was back ordered that I still don't have.
Still, this tank is a piece of cake to build.