I would have requested Chris Foss design
I'm just browsing "The book of Alien" that has Cobb / Foss concept designs, and I also have "Diary of a Space Person" on my personal reference book library - and I agree fully what you said about Foss! :)
Foss art (mostly from the DoaSP book):
http://www.masterpics.hpg.ig.com.br/anakin/cfoss1.htm
[Ron Cobb on the other hand is totally different case; I really like his designs]