The meaning and use is old, but it is from a time when accounts for companies were all logged into a ledger/book and reviewed by officials at the end of the year. Some companies didn't record all of their transactions for the year so when the inspectors were due, they would grab a new ledger, scribble in a years worth of data (probably ficticious) and when they were finished would literelly boil the books and let them dry to give an old and worn look, as if they had been used for the entire year. It was an old way of fiddling your accounts, and the phrase still pertains to the same thing today, just the methods differ.