Hi frlax

Here's what a quick search using Google yielded for me:

Mike and Melanie’s weekly etymological webzine:
http://www.takeourword.com/et_k-m.html#malarky

The Word Detective archive of questions previously answered (or attempted!):
http://www.word-detective.com/back-f.html#malarkey

bibliography to search for more details:
http://angli02.kgw.tuberlin.de/lexicography/data/slang09.htm

Hope you enjoy the board, and feedback if you find anything interesting about this or any other old malarkey