Parts List :

R*     -  See Text

R1     -     100 K

R2     -     100 K

R3     -       10 K

VR1   -        2 K Linear Pot

VC1    -    365  pF Air type

C2      -    100  N

C3      -    100  N

C4      -      10  N

L1      -    55 turns of 0.30 enamelled copper wire .I recommend Litz Wire                           wound on  a ferrite slab of  100mm X  20 mm X 3 mm for other                             dimensions adjust the  number of turns

IC 1    -   ZN414 or MK484 or TA7642(See Text)

TR1    -   BC108,BC547, BC548 etc.

Misc.   -  Crystal Earpiece (See text), mini on/off switch, One AA Battery and                    Holder,  3.5''Jack Socket ,Vernier Drive  ,Project Box

Volume Control

AA Battery Holder

IC Socket

Herewith is  the simple circuit diagram of my finalized version followed by an explanation of the important points that affect  performance.   

Litz Wire

Resistors

Capacitors

Calibrated Vernier Drive