Just wanted to update that we received the weights and everything's hunky-dory now. I was, admittedly, relieved that they were completely 'strange' to me, I didn't end up saying "oh THAT's the weights, well we had those all along" lol... Those were definitely missing from our balance.

My SIL has the balance as well and apparently hers came with the weights no problem, so it seems to be a one-time chance manufacturer's error. She even just got hers quite recently as well so they might even have been from the same batch. Thanks so much for your speedy and friendly 'patch job'! :)