It took years to get all of the issues, but I've finally been able to finish reading Madman. Of course now Mike Allred has started writing it again so so much for that, but at least I'm current.
Anyway the third and final volume of Image's reprint series has the lead tracking down his former mentor turned giant star traveling brain, entering into a tie-in with the G-Men from Hell movie (not so good but it did have Robert Goulet playing the devil), and meeting Mr. Gum who goes onto the spin-off book, the Atomics. There's also a thinly veiled guest appearance by Robert Rodriguez.
The stories are Allred's usual blend of fun adventure and pop surrealism and his art keeps improving with every issue. The G-Men from Hell arc is a little odd in that Madman is essentially written out of his own book for 4 issues, but is a decent story in its own right. Mostly these tales just further my already incredibly high opinion of Allred's talents