I found a great Married site (http://www.bundyology.com/) that answered a couple of questions that I've seen on the board. First is the song that Al couldn't get out his head is Anna ( Go To Him) by Arthur Alexander, in the episode titled "Oldies but Young'Uns". It's episode # is 5-18.
The Facts Of Life theme has appeared on two episodes
The first was "If I Could See Me Now"(episode # 6-07). It was the one where Al needed to get glasses.
The second was "Kelly Does Hollywood (Part 2)" (episode # 6-10). Kelly takes her cable acces show to Hollywood. The FoL theme appeared is an inside joke, MWC writers Richard Gurman and Katherine Green wrote for FoL too.