[E6] Post-lv6 Gestalt Rules?

In the E6 PDF, the author mentions a set of "quasi-gestalt" rules, which he didn't include because his players preferred to use feats.

I'm sure that feats are simpler and most players will go with the rule they most readily understand, but I feel like a good set of rules for buying gestalt levels after level 6 would make E6 a much stronger and more versatile ruleset. Even if it requires a lot of bookkeeping and few players choose to do it, I'd like to have the option available for the one or two builds where it matters.

Has the author ever posted his old quasi-gestalt rules anywhere? If not, how would you do it?

Simple, no book-keeping way: As one of your "Bonus Feats", you can take the following feat:

Eclectic Skills (Epic)
You gain the 1st level class features and spellcasting of a base class of your choice. You gain +1 skill point and +1 Hitpoint. The class skills of that class are now class skills for you as well.
Special: You may take this feat up to three times. Each time, you may either select a new class to gain the 1st level features of, or gain the 2nd (and then 3rd) level features of the class previously chosen. You gain +1 skill and hitpoint regardless.

- This gets the spirit of the ability (a high level Barbarian spreading out to gain minor spellcasting, or rogue skills; a Wizard gaining some weapon skill), but doesn't do the full effect (a Wizard wouldn't improve his BAB or HP by much, a Paladin will never become a full-on skillmonkey even with a few "Open Minded" feats thrown on later.

The "complicated" rules could be...
Epic Gestalt: Rather than grant bonus feats, you can allow players to gestalt earlier levels with another class. Every 5000 XP, the player may gestalt a new level. They gain the following benefits:

Base Attack: Your base attack increases by 1, if the new class has a better Base Attack bonus at 1st level. You cannot have more than a +6 Base Attack bonus in an E6 campaign.

Skills: You gain the difference between classes in new skillpoints. For example, if you are a Wizard and select Rogue, you gain (8-2=6) 6 bonus skillpoints. All skills that are class skills for the new class are class skills for you now. You still cannot have more than 9 ranks in a class skill or 4 ranks in a cross-class skill.

Saves: You get +1 to whatever is a "good save" for your new class that was a "poor save" for your old one. You cannot have more than a +5 base bonus to any saving throw. For example, if a Fighter takes a gestalt level in Cleric, he gets +1 to his Will save each time until his Will save reaches a +5 bonus.

Proficiences: You gain all weapon and armor proficiencies of the new class.

Class Features and Spellcasting: You gain all class features and spellcasting appropriate for a level in the gestalted class.

- Still not perfect, but an easily explained set of rules. Things get tricky if you allow multiclassing, so you may want to prohibit it to keep things clean.

Thanks for the reply! I like the way you did the BAB and saves. Much simpler than a true retroactive gestalt, which would probably be confusing.

I was thinking gestalt levels should cost more than one feat per level, maybe two per level or three per two levels. A rogue or wizard who gestalts Fighter1 gets back a feat from the fighter level, and then gets +1 BAB and a little HP/Fort save boost on top of it.