Making a new hat is not possible?

[oktobor]

Sorry if this is the wrong forum but I can't think where else to post this.

All I want to do is make a version of the desperado cowboy hat that has the same effect as the NCR 1st recon beret.

Seems like it should be pretty easy to on the face of it. Just open the geck, find the desperado hat, change the effect to the same one used by the beret, change the ID so the geck creates a separate item re-using all the Desperado hat stuff, place the hat in the game world, save everything and then go pick it up and put it on right?

NOPE!

For some utterly baffling reason the hat is floating NEXT to my characters head.
Queue five minutes of googling try to figure out where I went wrong.
Discover a 9 year old tutorial on using FNV edit to fix the so called "wonky hat bug" follow the tutorial and now My mod doesn't exist in the Geck.

I load the Geck back up and no mater where I look my custom "Lucky Cowboy Hat" isn't in the item list. I made double and triple sure to have both the New Vegas ESM and my own ESMs loaded but it doesn't appear anymore. Get frustrated, delete my ESM and repeat all of the above again only to have the same problem happen again. My ESM despite being loaded according to the geck contains no items.

After spending an entire afternoon working on something that should only take 5 minutes tops I give up.
Can someone just make the mod for me or point me to another mod that does something similar?