Pop quiz: What is Toile de Jouy?

Aaaack! There are so many things that I don't know about in the world! Like Toile de Jouy. Do normal people know what this is? Do normal French-speaking people know? This is what it is:

Or this:

My god. Would you sleep in a room that looks like this? But anyways. Is it common knowledge, that this is Toile de Jouy? To me, what it looks like is Delft Blue patterns but in a fabric print version rather than on ceramics. In the novel, there is repeated mention of a Toile de Jouy sofa (by the way, who uses the word sofa? Doesn't everyone say couch?), and I want to be as accurate as I can to the text, but would talking about a Toile de Jouy sofa just make people scratch their heads? Does it matter? I could even go so far as to translate it as damask... would that be falsifying? They look basically the same (to my undiscerning eyes)!

Also. In reference to an octogenarian internet user, the novel talks about her typing on the keyboard "comme sur son engin de sténographie." What the heck? At first, I thought it was talking about a typewriter. But no... stenography, apparently a lost art. This is a whole world that I know nothing about. Are stenotype machines still used? I founds some photos of old ones:

OK. Pop quiz: who is the Count de Saint-Germain? If I was to tell you about an advertisement for Count Saint-Germain elixir, would you know that I'm talking about a potion that gives the drinker eternal life? Count Saint-Germain was a German guy who apparently discovered the secret to eternal life. Is this something that I should explain? Or let people figure out for themselves if they so desire?

The problem with leaving things up to chance like that is that I, personally, am not the kind of person who will go look up an obscure reference from a novel I'm reading. I will let it slide, and try to understand what's going on via context... and because I am this way, I feel like everyone else is as well. And although I understand that the narrator of this novel is trying to be obscure in order to prove how erudite she is, I also feel like it's necessary to make sure that the reader knows what she's talking about. Is this not true?