You could start out by researching the Rowman (as benduwan has stated above) & the Dr. Gonzo sets ..... I believe they had a fair amount of the LD only features collected from the various releases.
http://originaltrilogy.com/forum/topic.cfm/The-Official-RowMan-Release-Thread/topic/2947/
http://originaltrilogy.com/forum/topic.cfm/The-Dr-Gonzo-Trilogy-DVD-Info-and-Feedback-Thread/topic/1382/
This page may be of some use to you as well .....