This is sad and fascinating at the same time -- sad obviously because it's in such a decrepit state, but fascinating because it must have been quite charming in its day, and of course because its day was in the 1700s. That's a long time for a piece of knitting to survive! I find it very poignant that the museum titles it, "Worn and patched sweater" as though those adjectives are now more significant than any other -- and indeed, they give no information about colors, fibers, size, which on other pieces they can be very meticulous about. The only other information is that it is from the Årstad district in Halland, which is one of the traditional provinces of Sweden, on the western coast in the southern part of the country.
The "carnation" pattern will be familiar to those with a penchant for Scandinavian knitting -- a chart in Sheila McGregor's Complete Book of Traditional Scandinavian Knitting is I think almost exactly the same, and similar carnations appear in Britt-Marie Christoffersson's Swedish Sweaters.
This jacket is in the Nordiska Museet in Stockholm (inventory no. 134916, and apparently also NMA.0041484), by way of DigitaltMuseum.