I love the idea of a dagger busque! I knew a girl who did her thesis on commedia d'larte, and she carved a busque out of wood. she had no friends and a lot of time on her hands. she didnt need to do that.
I think you are asking all the right questions. The most important thing about "historical accuracy" is not exclusively drawing from primary sources, it's making sure everything makes sense. Just like when you do worldbuilding in fantasy/scifi, make sure your world makes sense. If she has a dagger busque, what does that feel like when she bends over? I'm so happy you posted "the great" because i loved the costumes on that show. The costumes have RULES. Catherine is allowed to wear a peasant blouse in scenes where she's not at court. She can dress down when she's alone, but when shes with peter shes got to dress up. If she's seeing the ladies she's got to dress EXTRA.
reasons you cant trust primary sources:
-the extant period clothing that survives in museums has survived because it was never worn. it was either a one-time event specific piece (like a wedding dress), or it was ill fitting, or the owner didnt like it. A lot of extant gowns have tailoring flaws which explain why they were never worn. a lot of extant clothing is UGLY. I can imagine the 1870s woman whose gown is now in my museum being like "green, mother? this is the ugliest shit ive ever seen. ew. put it in the trunk." The costume collection i used to work at was largely a collection of clothing too ugly for people to wear
-preservation bias. pieces that were saved because they were special, and do not represent everyday fashion. We were thrilled to find an 1850s wedding gown that was STUNNING. it did not fit conventions of the time period for wedding gowns but it was STUNNING. Im going to write stunning in all capitals again. STUNNING. so anyway i wanted to write a paper about how unusual it was but when i looked up the provenance it was made by a textile merchant for his daughter's wedding. it was only unusual because they wanted to show off how great dad's fabric store was.
You should feel empowered to make your own rules, because individuals make unique clothing decisions based on their needs. There's no primary source for your original character. As long as your character rules make sense, you should be allowed to get away with it. And you should have rules. you should have a lot of rules. if your character is neurotypical, they probably dress differently depending on the situation. who are they meeting? what are those people gonna wear?
another note about your time period: you already know about separates, right? so youre looking at 1 piece of every clothing item, maybe 2, and they swap out. you could plan out their whole wardrobe if you wanted to, and i bet you already have. Any fabric you could see would be pretty, the interior layers were whatever they could get their hands on. Interior is butcher's cloth lining for rich people, anything for poor people. I found a pocket cut out of a feed bag in an 1850s dress. you could put a feed bag in your story if you want. you could do anything, lol.
i cant tell you exactly what your 1780s girls are gonna wear, because its gonna depend what their tailors could get their hands on. I can give you resources for costume design if you want, but you dont need it. where is their tailor? how big is their staff? how much time do they have? i assumed basques were a high court thing, provincial gals wouldn't have had that. what would colonials make stays out of? what they could get their hands on. oldest corsets Ive handled are 1870s and they had no bones, only reinforced cotton. then again, survival bias. maybe the boned ones didnt survive, and thats why their descendants only had non-boned ones to donate.
i can send you 1890s if you want primaries. my fav provenance story is an 1890s piece by a woman so rich she bought fabric in paris and then left it in a trunk for a year, because wearing the "newest" fabric was considered too "noveau riche." thats was a real thing people did. give a fuck about other people's opinions like that. im like, "girl if you got it, flaunt it"
