Another version of Heathkit IG-5218 ?

I just purchased a Heathkit IG-5218, it has been modified with switches to disable the meter and square wave generator. I cannot find this version on the net, it has 18 transistors on the oscillator board, and vertical pots instead of horizontal the date codes on the caps is from 1977.
Has anyone seen this version? I am looking for any info on the unit for calibration
 

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I just purchased a Heathkit IG-5218, it has been modified with switches to disable the meter and square wave generator. I cannot find this version on the net, it has 18 transistors on the oscillator board, and vertical pots instead of horizontal the date codes on the caps is from 1977.
Has anyone seen this version? I am looking for any info on the unit for calibration

Check and see how well it matches up with this one:

http://waltjung.org/PDFs/Morreys_Super_Oscillator.pdf
 
Awesome! even to the pcb! Thanks!

It was too easy! I converted an IG-18 to a Morrey in the day (1975) based on the circuit boards shown. I later on developed a far simpler enhancment based on 5534 ICs and light-bulb stabilization.

This was followed by investigation of the use of CdS cell based opto-isolators, FETs, and analog multipliers as stabilizers, given that the basic performance of the Op Amps were the not limiting factor.

Ironically, at the same time I was part of a local group developing ABX testing which proved to many of us the futility of chasing after the last < 0.001% distortion.

In the end, it was all replaced by software using professional audio digital interfaces.