Happy birthday Russ!!
Do you still have my email address to hand? if so, please can you remove the top cover from over the spur, take a photo and email it to me? If you can include the whole length of the layshaft from directly above, then I will confirm if built right - and if not, take a photo of my car and email it back to you.
I am not doubting you, but without the car in my hands its hard to diagnose a fault so starting from the basics is the easiest way..
Also, will you be racing between now and the Southport GP? As I will be there and will gladly go over anything then for you mate.
Chris