If the person who uploaded the file included the model number in the title, as a tag, or in the description field, search will find it.
I envisioned the Downloads section to be a collaborative effort that was entirely driven by search. Hence just one category called Pot Luck Supper. The key to that working effectively is for the file contributors to be conscientious about the meta data they include with the file. For example, adding all applicable model numbers in the file description, adding all applicable tags such as brand type of appliance, etc., adding the publication number in the description field, and things like spelling out the word "refrigerator" instead of just saying "fridge" (or if you're going to just say "fridge" in the title make sure to add the word "refrigerator" as a tag).
The Downloads section is a community effort. I'm just one of the contributors. I ain't nobody's momma here and I don't play one on TV, so the Pot Luck Supper will be as messy or tidy, as useful or useless as you, the file contributors, the community of users, make it.