From Dictionary of Phrase and Fable:
Don’t come the uncle over me. Do not overdo your privilege of reproving or castigating me.
Laid out in lavender means prepared for burial. The phrase has also been used to mean ‘show something in the best possible light’.
The City in Slang: New York Life and Popular Speech by Irving Lewis Allen says that to lay out in lavender also means to pawn some good: http://books.google.com/books?id=j41z0yeKbeIC&pg=PA159&lpg=PA159
From Dictionary of Phrase and Fable:
Phrasefinder says,The City in Slang: New York Life and Popular Speech by Irving Lewis Allen says that to lay out in lavender also means to pawn some good: http://books.google.com/books?id=j41z0yeKbeIC&pg=PA159&lpg=PA159