Engine problem progress

I might have found the problem with the car. I was doing a compare and contrast between my NOS carb which I fitted during the rebuild and the one that came with the replacement engine and which I removed at the rebuild but have now refitted to the car.
In the lower half of the carb casing there is a drilling in the side wall that feeds fuel from the accelerator pump to the top half of the casing and onward to the various venturi. Missing from this was a small brass plunger that presumably amplifies and\ or regulates the flow of fuel through the drilling. Presumably its absence could have led to flooding of the carb and its' cutting out; Paul Medhurst at Type 3 Detectives has confirmed could be possible.
I have taken the brass plunger out of another carb and it has now been re-tuned following which the engine seems to be going OK when really warm but still stationary without any load.
Here is a picture of the NOS carb showing the brass plunger resting outside of the drilling in the top right hand corner.
I won't be able to test drive it until Thursday now and so I have a neighbour on stand by to get the car to the VolksWorld show by trailer on Friday if I have further problems. I don't like having a trailer queen for a car but having committed to get it to the show that's what I'll have to do.