The conceptual mock-up figures are discussed in Plastic Galaxy so I'd highly recommend owning that DVD. The catalog photo you show here is a mix of Kenner versions plus mock-ups. There are more shown here, including all of the conceptual mock-ups, not just the final 3.
http://theswca.com/images-concepts.html
The Jawa is essentially a brown sock and the Death Squad Commander and Tusken Raider were made from Fisher Price Adventure People. Check the link I showed for images of the others. The descriptions have more details, especially the Luke.
Here's an early Meccano catalog group shot:
http://theswca.com/index.php?action=disp_item&item_id=48959
Interestingly, Kenner even used a Fisher Price figure to mock up Luke X-Wing Pilot for the 2nd wave:
http://theswca.com/index.php?action=disp_item&item_id=48958
The TIE Fighter you show is a handmade styrene model built in Kenner's Prelim model shop. An artistic representation of it is used on the 12-back cards. Here's the original artwork:
http://theswca.com/index.php?action=disp_item&item_id=78520
Cheers,
-chris