It's very, very common to find attachments that with other machines mixed together.
Based on the style of ruffler, #4, this set is most likely to fit a machine made by National (and they sold them with over 600 badge names). However people often combined parts as they got a new machine and kept the attachments for the one they had before that. I would assume that sometimes someone got ahold of a vintage machine, and picked up vintage attachments at a thrift store with no clue what they fit - and just put them with the old machine.
Learning to identify old attachments is the main reason I've got such a variety of machines. The top clamp style came in a lot of variations. Most are either White, National, Standard, Free, New Home (before Free took control) but there are quite a few others that are much less common. Older machines took feet that had round holes in the top, and slipped onto the bottom of the presser bar. For US machines of the time, Singer was the odd duck with the side clamp feet. However that was the common method for European machines.
The next step is learning to identify the add on attachments - those that are much rarer and worth way more. Most times the basic set came with the machine, and the sewer bought additional ones as needed. So you'll find a rare attachment tucked into a box along with the basic set.
I picked up a single thread and double thread embroidery attachments in a cabinet with a beat up old Singer 15-91 - for $32.50. Those two attachments combined, sell on eBay for over $700. I didn't want the machine, but when I saw what was in the drawers, I couldn't get it loaded fast enough!