Work in progress. It's pretty much just a proof-of-concept at this point.

It works! (Sort of...) Now with steel, blades, ebony, daedric, and dwarven swords. You can now wield a one-handed sword with two hands. And it looks exactly the same either way, but has better stats 2-handed. The two-handed versions have 1.1 speed (normal 1-handed swords have speed 1.0), and base damage x 1.5.

What it does is: it gives you a power that, when used, swaps your one-handed sword (which must be equipped--in your right hand. Doesn't work in the left hand--not sure why...) for a 2 handed version, and vice versa. You can toggle back and forth as often as you want. (Well, some aren't switching back at the moment. Have to fix the script...)

It currently only works with some swords. Will finish all base 1-handed swords soon. Not sure what will happen if the sword is improved or enchanted.

If you want to test it, activate the mod, load your game, then open the console and type "help switch" to find the power "Switch Grip" and "player.addspell" to add it. Then equip a steel sword and use the power. (Not sure if it has to be unenchanted/un-upgraded.)

Also, need to figure out how to make a power automatically added to the player. Checking the "Player Start Spell" box doesn't do it, apparently.

Thanks to JDFan on Bethsoft Forums who explained what I needed to do to make this possible and how to do it.

Changelog
v0.04
-Works for elven, dwarven, ebony, daedric, and blades swords.
-All the altered models/items are done for all the base 1-handed swords (I think). Just haven't finished setting up the script for all of them yet. It's tedious!
v0.03
-Should work with normal steel swords now.
-Two-handed steel sword is now named "Steel Sword".
v0.02
-The 2-handed sword now uses the 1-handed sword model.