. . . So I've had the truck running with the choke slightly out and I've tried adjusting the two idle screws but it doesn't seem right . . .
There is only one idle screw and one mixture screw.
The idle screw adjusts the "lever" that is attached to the throttle-rod/gas-pedal. This adjusts the "idle speed" - the RPMs at idle.
The mixture screw adjusts the air/fuel mixture. I think it is recommended that you gently turn this all the way in - gentle turn it in until it "stops". Then, back this screw out 1.5 turns of the screw.
Larry would most likely have set the mixture screw close enough to get the engine started.
