Every mystery writer (and reader) goes back to the classics, to enjoy another time, to take a breath or to recalibrate. Just doing it for fun also counts.
I am currently reading The Maltese Falcon for the first time in about 15 years, with The Big Sleep in paperback waiting for a trip next week. But why reread books where the first sentence reads like a cliche? Because of all the other people who tried to write a sentence as good, and never could. The Mona Lisa is a visual cliche, but worth all the time you can give it for your second or tenth look.

I've always thought Chandler used the mansion on Franklin Avenue that is now the Magic Castle for the Sternwood mansion in The Big Sleep. It just fits too well. I would recommend your exploring the Castle (to determine your own opinion on the Sternwood question -- of course).
I have stood on the plot of ground where Miles Archer's body was found. I have eaten Sam's Chops at John's Grill while having a beer at the bar where Hammett customarily drank his lunch. Sam's Chops is the meal that Sam ate in the Falcon before running off on a wild goose chase on the Peninsula. While you are at John's grill, go upstairs to see the photos and displays regarding the movie and Hammett. The third floor used to be for a jazz night, but I'm not sure if that happens any more. John's is one of the last 2-3 old style grills still operating in the City. Brass, mahogany, and only waiters, not waitresses, and a great but limited menu.
Have you read Chandler's 1956 review of Fleming's James Bond creation? He thought Bond was an excellent creation, and that the first three novels were solid, but the fourth, Diamonds Are Forever, had a great title but read like a standard American gangster novel. (Chandler was writing in the Sunday London Times, Narch 25, 1956.) He calls Bond in this novel a character "as atmospheric as a dinosaur". The punch-line to Chandler is that the amazing thing about this American novel was that it was written by an Englishman. He then advises Ian Fleming not to be a stunt writer, or "he will end up no better than the rest of us".

While finishing my current novel, I am beginning working on a thriller novel set in 1988 in London, Paris and the French Countryside called 34 rue St. Dominique, which has a major sub-plot I haven't seen used in any thriller, i.e., the French Gestapo. I'll talk some about the French Gestapo next time.

BTW, the best brief work on Hammett and Chandler is Robert B. Parker's The Private Eye in Hammett and Chandler, Lord John Press, 1984. A signed private printing, I have #282 of 300 copies. It is a remnant of his Ph.D. thesis of the same title with a misspelling on the first page, but what the hell, it's only ink.