I too sought to put a little bit of the Original Fallout games into Fallout NV a while back. I've played very very little of the old games (perhaps a few hours or so) and I wanted to experience something similar in FNV because I liked the style the old games had.
Anyway, here's what I used:
Revelation - Makes the menus look like Fallout: Tactics.
Classic Fallout Weapons - A little bit old and somewhat lowres, but a lot of the weapons from the originals fit so well in NV.
Pipboy 2500 - Replaces the wristmounted Pipboy 3000 with the handheld Pipboy 2500. If you don't like handhelds, the author has also uploaded a wristmounted edition of the 2500.
Fallout 1 and 2 Classic Ambient Music - Self explanatory, it replaces Inon Zur's music with Mark Morgan's music.
Classic Fallout description messages - Brings back the description messages. I'm not sure if this works in all areas, as the description listed it as a beta and it was last updated in 2011.
XRE Cars - Now your Courier can ride in a Chrysalis Highwayman.
Hope this helps
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EDIT: As far as I know, I do not know of any specific leather armor retextures but here are Macintroll's wasteland clothing hires retextures.