I don't know about the coating - although I had an old-type 50/4 for a while years ago, I've never had the opportunity to do a direct comparison of old and new types.

Re barrel cosmetics, easiest just to point to some photos.

Scroll down on this page for a picture of the N-type 50/2.8:

http://blogs.salon.com/0004217/2004/11/15.html

Scroll down on this page for a picture of the old-style 50/4:

http://www.mir.com.my/rb/photography...or/index10.htm

The picture on this page is the A-type 150/5.6 - possibly a mismatch to what's actually being offered:

http://www.adorama.com/US%20%20%20%20360982.html

A lineup of older macro, micro and EL lenses, with an N-type EL at the far right:

http://nikonhistoricalsociety.yuku.c...-mm-f-3-5.html