One thing that will help push this card over the edge is the unrestriction of Chrome Mox. 

There are several constraints to playing Ad Nauseam:
1. You must be able to consistently generate not just 5 mana, but 3BB.
2. Your curve must be on average, lower.
3. You must be able to turn drawn cards into resources

Chrome Mox dovetails with these constraints because it:
1. Generates colored mana
2. Lowers the curve
3. Turns cards into a resource (mana)


Sample theoretical list:

4 Chrome Mox
1 Black Lotus
1 Lion's Eye Diamond
1 Mana Crypt
1 Mana Vault
1 Mox Emerald
1 Mox Jet
1 Mox Pearl
1 Mox Ruby
1 Mox Sapphire
1 Sol Ring
1 Memory Jar

4 Polluted Delta
1 Swamp
1 Tolarian Academy
2 Underground Sea

4 Ad Nauseum
4 Dark Ritual
4 Cabal Ritual
4 Duress
4 Thoughtseize
3 Grim Tutor
2 Tendrils of Agony
1 Rebuild
1 Vampiric Tutor
1 Ancestral Recall
1 Brainstorm
1 Imperial Seal
1 Demonic Tutor
1 Time Walk
1 Timetwister
1 Tinker
1 Yawgmoth's Will
1 Necropotence
1 Yawgmoth's Bargain

Average cost of each spell: ~1.5

This is based off the Grim Long shell, but has a few key differences.  You need to run less land so that there are more things to imprint on Chrome Mox, but it works out because that means you need to run more rituals, all of which can be imprinted.  All of this is untested and would need serious tuning, but I think it has the right concepts to best abuse Ad Nauseam, turning them into Bargains 2-5.

Sigh... silly vintage players.  Personally I think it is good thing that Wizards slips some planeswalkers into this format - shake things up a bit.