What was the source of Bilbo’s income in The Hobbit? (By the time LOTR rolls around, Bilbo is living off of his proceeds from [spolier]whatever he could loot from Smaug’s treasure[/spoiler]).
Bag-End seems to be almost a mansion by Hobbit standards, and Bilbo never seems to want for food, wine or other comforts. He has enough money to hire a gardner (Hamfast Gamgee), and he leaves a pretty sizable estate to Frodo, who also hires a gardner (Samwise Gamgee).
However, none of the four books (IIRC) mentions Frodo or Bilbo doing anything to support themselves. My guess is that Bilbo’s father (Bungo Baggins) must have been a wealthy merchant of some kind, or perhaps a vintner (in the movie, and possibly the book, Bilbo mentions a bottle of wine being “laid down by my father”), and left a lot of money to Bilbo.
So, does anything in the Hobbit/LOTR books, or other writings by Tolkien, hint at what Bilbo and/or Frodo did to support themselves?