The Fine Waistcoat cosmetic is a full set, comprising a waistcoat (obviously), trousers and shoes. If you're a Hobbit, the shoes do not show, however. Aside from the ruffle on the collar, this upper body cosmetic is not overly fancy, which is good to see.
I have not tested whether gloves work while wearing this outfit, but often they don't with such items. Do let me know if you have tested this and what the result was. I'm happy to thank/credit you. However, because there are shoes (or a lack of them) as part of the Fine Waistcoat, you cannot add your own footwear.
Acquiring this Cosmetic
While this can be bartered for 10 × it also has a chance to drop from a Platinum Gift Box (costing 5 × ).
If you're a member of the Ale Association, you also have the opportunity to buy it for 5 × Badges of Dishonour.
How Well Does It Dye?
Very well, per the Wiki, where they have dyed it Violet - and shown it on a Hobbit too.