Children's Book From Early 1980S - Boy Covered In Stamps

[luckystrike]

I'm trying to remember a book that I read as a child in the early 1980s about a boy or girl who covered their younger brother or sister in stamps and tried to post them somewhere.

Any ideas?

[rockyracoon]

Superfudge?

http://en.wikipedia.org/wiki/Superfudge

[birdwoman]

Flat Stanley? http://www.flatstanleybooks.com/