Dan,
I think you're right, the Sunbeams did have a bit better build quality than the BMC stuff. Even then, 60s build quality everywhere in the world wan't the best. The clip of the car I posted is a car for sale at $129k. That fuel leak is scary to say the least. And once it's fixed, I'd think about changing the air filter as Grantura states. They are rumored to go up in flames with a carb backfire. So maybe our build quality isn't any better.