FW, welcome to the HoC! You may be ... just may ... be the first member here with an actual SAE. And what a beauty! There's not a great deal in our database (that I know of) about the strictly SAE guitar. Short lived, I know that. The SAE was incorporated later into the Millennium guitars - as I have a Millennium SAE. Much like your guitar except it does have a selector switch and a slightly different body style. You could always call the guys at Heritage (yes, call them, you'll be surprised by their accessibility) and ask Ren about your guitar. 269-385-5721.
My guess is your controls are Vol-neck, Vol-bridge, Vol-piezeo, Tone. Interesting that there is no selector switch. Still, congrats on such a beautiful and somewhat rare Heritage guitar.