Using variants not quite how they were meant, looking for a better solution

I am selling antique desks, which are one of a kind. Customers can buy the desks as-is, but typically they’re pretty beat up. But I also offer the option to paint the desk with high end paint.

To achieve this, I’m using variants. My typical variants are color and sheen, so there’s a variant for Black / Matte, Black / Satin, etc. The price is different depending on the variants.

My issue is that variants are not meant to represent a single item, they’re meant to represent a whole bunch of physical items, like small/medium/large t-shirts. So I either have to:

  • Mark every variant with a quantity of 1. This doesn’t work because as soon as one of the variants sells, all of the variants are effectively sold, because there’s only one item. This also throws off my inventory pricing, because it looks like I have 1 of every variant.

  • Mark every variant with a quantity of 0 and check “keep selling after inventory is 0”. This isn’t ideal either because again, after a variant sells, the product stays up for sale and someone can come try to buy it again, and the shop will let them.

Is there a better solution to this than using variants? I feel like this is not the use case that variants are there to solve, but I’m also not aware of a better solution.

Thank you!