More so how many total, understanding that they'll need to be moved top/bottom when setting weights. Also is there supposed to be a spacer under the washers or do washers sit right on the block
Pretty sure no space block, provided you didn't loose any washers count total thick and thin and divide both by 2, that might answer your question.
Good luck !!
Really doesn’t matter as long as ALL the gap is taken up. In theory you could have twice as many in one side than the other depending on how many thick and thins. I will go on record and say the 1/4” spacers are very nice and make cross adjustments way easier!