Mineoro DC2008

[Geo]

Hi.
Today a friend gave me a DC2008 to modify it. He wants to replace the sensitivity potentiometer with a multiturn one.
I opened it and i saw that the previous owner had open it and had remove the black resin from the receiver pcb.
Also i saw that there is a problem with the oscillator (2N2646).
So i said that it is time for a reverse engineering until i receive the multiturn potentiometer.
I Must tell that my friend found some small objects (ancient coins etc..) with it at small depth (10... 30 cm).
I attach some photos from it...

Regards