To separate the idle cam from the choke

How about a small (they make them LOL) gearhead 12V motor connected to a replacement curb idle screw. So long as the motor electrics is isolated from ground (such as PM with two commutator wires) all you need is a momentary, center off, DPDT switch to reverse/ forward the motor, and screw the curb idle in/ out

Such as

DC Motors | MPJA.COM

12VDC, 5 RPM Gearhead Motor ZGA37RG244i | MPJA.COM