JDW, the pictures referred to show the decoder. Before there were little decoder boards made, people piggybacked an additional 7AS153 atop the one at F3 as in this photo:

http://homepage.mac.com/henryspragens/.Pictures/Macs/100_0398.JPG

http://homepage.mac.com/henryspragens/PhotoAlbum17.html

You might find this article interesting, too:

http://homepage.mac.com/henryspragens/PhotoAlbum16.html

And yes, it was me upgraded Andy's Mac to 1MB as mentioned at Folklore.com. We upgraded a lot of Apple engineers' Macs.

We also made unmodified 128Ks valuable by making them scarce.