Just a minor caution for anyone rebuilding Mk1's with new bodies. When I assembled the newly tooled bodies (about 2 years ago) with old (8 yrs) parts I had an issue with floats sticking up or down. Turned out that the width of the float across the pivot pin area was wider than the body (not the bowl) casting. I had to remove material from the body to allow float to pivot properly. That solved one problem but it recently came back on one carb which was sticking occasionally.
Just pulled them apart to fit Amal new aluminum needle valves and found one float sticking on the pin. It would move but not freely. The pin was straight but the float holes were not in line and needed reaming a little. I had never noticed this but since the pin is lightly trapped by the gasket and normally cannot turn the float has to move easily on the pin. Obvious really but missed by me. Maybe the plastic has distorted slightly with time. Took a 3mm drill to open up enough.