Here's a Sheraton listed on Yahoo Auction. I know our gracious host doesn't want ebay links posted (well this technically isn't) however, I wanted to show this for the sake of IDing Matsu Epis, and because you were interested in pickup photos (wish they were clearer.)
83 Sheraton
The seller, a music store, states this is a 79 based on the pickup cavity number. That's the same confusion I had as my Casino has a 78 written in it. After much research, I found that Matsu/Epis started a serial number year ID system in 1980, so this Sheraton is a 1983 (January.) The 79 is a production identification number. I downloaded about 30 pictures of Matsumoku hollow body Epis and studied them carefully (including all of Tads.) There was a change in specs and finishes in 1980, so I'm sure this is an '83.
Also note the microtuning tailpiece. I've never seen one of those on a Sheraton, Matsumoku or otherwise. Actually this would be a Sheraton II with the stop tailpiece. My guess is that it's original, either custom order or one of Uncle Matt's unique contributions. It seems that even though Matsumoku was a mass production operation, they always added a little character to every guitar they made.
BTW, if you click on the seller's name, guitarmanias, and look at his other stuff, you'll see a Yamaha SG-2000 (currently in high demand in Japan.) There is a link between Matsumoku and that guitar, but I haven't quite figured it out completely. I believe that either Matsumoku engineer Hayashi (H. Noble) was on the design team, or that the entire guitar was designed by Matsumoku's engineering staff.