That's the best I can do to help as I mentioned in the PM I sent you, I am an antique slot machine guy covering the 20's/30's/40's and I don't usually touch anything that has electricity attached to it. You may want to contact the site to make sure it is the correct manual. Scroll down to MILLS open front manuals or 'M' head manuals. The site address is I believe - /page21.html. If you search the web looking for 'Mills open front slot machines' you may find more information and there is a web site called 'The Sugar Shack' which may have a manual for that machine. I believe made in 1961 in various varieties of cabinet signage.

Having what they referred to as an 'M' head because of the shape of the coin entry head. O.K., the only thing I could find on this machine tells me that it is a Mills 'Open Front' slot machine. $200 - Did I get a deal? And does anyone have any idea what year this is from? I'd think late 50's or early 60's. Pictures.taken right after unloading it from the car. The cabinet needs work but I think I can clean it up quite well. And.to top it all off, when I released the lock to the cash box, it had a bunch of paperwork and a book on repair of Mills mechanical slot machines. I pressed down on the lever where the handle goes and the mechanism went through complete cycle perfectly. It didn't work but I was very happy to see the the entire mechanism slid out easily. The belly glass and reels are also illuminated. No key was included but when I got it home, one of my replacement lock keys fit it! I got it opened and saw that there was a coin comparator and a handle release mechanism, which appears to be solenoid actuated. I immediately called machine was still available and, within a half hour it was in my back seat and now the garage. Merrymaker is the name on the slot machne.

Didn't know exactly what this was from the ad:

Monti's slot shop