Parts list for a miniature low rate speed control, designed by Keith Walker
Resistors
R1: 100 k
R2: 10 k [Tracy Narine had to use 22 k to get full throttle with his radio]
R3: 10 k
R4: 10 k  (variable) linear trimmer pot
R5: 10 k [possibly 1 k ?]
R6: 10 k
R7: 4.7 k
R8: not on the diagram!
R9: 10 k [Tracy Narine suggests 1 k instead]

Diodes
D1, D2: 1N4004

Capacitors
C1: 0.1 uF, 6 V 
C2: 2.2 uF, 6 V
C3: 10 uF, 6 V
C4: 0.01 uF, 25 V

ICs and transistors
Q1: 2N3906
Q2: IRFZ40 or equivalent
IC1: LM 358