Glaser Steers cabinet cutout

Does anyone have a template they can trace or otherwise copy to make a mounting board for a Glaser Steers GS-77? Actually what I have is the HeathKit AP-3, but the same thing in essence. Also, does anyone know which cartridge was originally used in these changers where the "78" stylus tab pressed into the armrest post to activate the "SpeedMinder" feature? I'm VERY HUNGRY for some more resources and information for parts, company information, etc.
Beautiful machines, wonderfully styled, unique features.

I used to make mounting boards just by placing the changer on a piece of plywood, and figuring where stuff needs clearance or support.

- I made an outline of the plinth for a guide. I then used toilet paper tubes to hold up the changer, using the floating spring locations.

- I marked the locations of the springs by drawing around the toilet paper tube ends on the board.

The spring pads, and any transit screws, are the only parts of the board that are actually needed under the changer. The rest can be cut away. But if there is a large area with no mechanism, the board is stronger if it is not cut away. Also, it looks better if the cut parts of the board can't be seen by the users.

- Pay particular attention to the motion of the trip finger. That changer has the longest trip finger I ever saw. Also note the change cycle slide, and the overarm end.

- Leave about half an inch clearance for moving parts, and a quarter inch for stationary parts. Ignore parts that never protrude below the edge of the plinth.

If you had two cartridge slides, one for standard groove and one for microgroove, a speed probe attached to the standard groove slide - a necessity for magnetic cartridges. And the cartridges with the flipover tab about half an inch behind the stylus worked.

Toilet paper tubes- excellent idea! Currently it is resting on inverted coffee cups while I clean & lube it. This is the HeathKit model- there are no cartridge slides, only 1/2" tapped holes for mounting, so adding a probe to hit the 78 sensor won't work. I like the Astatic 17D- reasonably high compliance for a ceramic cartridge, but the 78 tab won't hit the sensor. I only thought of using a magnetic cartridge in passing for this since the arm has such a high mass and a spring tension pressure adjustment. No anti-skating control either. I just don't think this arm is suitable for anything too fancy, especially something with an elliptical point. Yeah, that cycle trip finger is incredibly long, ain't it?

When these were made, only one tonearm was made with antiskating. It was a Shure manual arm.

I've owned a Glaser-Steers GS-77 for over 35 years. It was my father's - he bought it in 1958 brand new. The most common cartridge used is a GE VR-II (old VR II, although the new VR-II will work. It's a monaural magnetic cartridge. The way it works is that the cartridge has a 'T" bar that holds the LP stylus on one side, and the 78 rpm stylus on the other. By pushing down and turning, you can select LP or 78 stylus. I've loved this record changer for it's functionality, and still play 78's on it A few years ago, regrettably, something got accidentally bent because the tone arm can't lift up from it's base (without a manual lift) to play the record. I've been using it manually.

Also, the Speed Minder function was to determine 33 or 45 rpm, not so much 78 rpm...