Lumpert opened a catalogue from SARONIX and noticed the NYP 041 12. That quartz operates at about 4 MHz and that is just the frequency he needs.
Lumpert ordered 20 quartz from COMPONA AG (A retailer of the SARONIX NYMPH quartz) on 13 August 1985. You may remember that he had ordered 20 boards from Thuring on the very same day.
Later on, on 8 November 1985, he will order 15 identical quartz from the same company.
Notice that the invoices and the catalogue give the frequency of the quartz as 4.194303 MHz. But look again at the picture of the timer “found” in Togo!
The quartz is clearly labelled 4.194304. What is going on?
And keep in mind that Lumpert had clearly written 4.194304 on the circuit diagram he had just designed.