Wasn't it you who wanted to put a model on Tenguman, though?
Just saying.
Either way this suggestion is literally my fault because I am probably the one in the community who dabbled with models the most.
The only things in the entire game that warrant a model would probably be the yoku blocks in Heatman and maybe the guts lifts.
(https://dl.dropboxusercontent.com/s/36qjxwg7pgwlxuf/Screenshot_Doom_20130804_183505.png?token_hash=AAGcNKmKOYLH-Ddon46Kz-tJCZ-FvO-G2SRR61-JrBUASg)
(https://dl.dropboxusercontent.com/s/l5ychhkl5mw7pxw/Screenshot_Doom_20130804_183634.png?token_hash=AAHQyJYSQGnQRRORuItk-9TD6kQiTMpCnNYwfbjkLsLZMw)
Not saying this should go in the core, but it definitely makes for a fun [and fps killing] mod.