HelenAnn- I have way more boxes than machines they would have come with. Singer didn't offer the puzzle boxes for all that long, maybe 10-15 years (1890-1905). And during that time they sold with the VS/27, IF/15 and there is one box for the 24. Singer appeared to stop using the puzzle box about the time they came out with the 66.
The good part is that a style 11 set will fit newer machines, and I think a lot of people kept the boxes when they upgraded machines. There are way more puzzle boxes out there than machines they would have been sold with. But then there are way more WW boxes (mostly empty) out there than WW #8 and #9 machines too.
Style #9 has a slide for a fiddle base machine, and the #10 comes with a slide for a rectangular bed machine, so that gives a nice dividing line.
Style #11 for the 27 is the most common (by a long shot) of the puzzle boxes. From watching on ebay, it appears that style #3 for the VS is the next most common box, though #11 for the 15 is not hard to find either. Boxes 7-10 show up much less often, and 1, 2 and that for the model 24 are very rare. I've found some indications that styles 4,5,6 were not puzzle box sets. It's possible those were internal numbers for Singer, as there does not seem to be any separate instruction booklets on them like there is for #7 - #11.
On a side note, I am working on matching up a set of attachments for each machine I have in the collection. Those will be on display by each machine. I've got 2 versions of the fiddle base IF and a VS1 and VS2, along with a 27, and an early 24 hand crank. So that gives me 6 machines that were from the time period of the puzzle boxes. However I have 14 different puzzle box sets that came out during the same time frame as those machines.