I think perfection is just a different word for a feature of quality. Like you said St. Paul, for me that means durability and ease of use. I think a lot of people fret more over the outward look of an engine but do not worry about the long-term durability, as for them it graces a shelf rather than getting oily and running more hours. Ultimately I think we can all appreciate the "perfect" engines that have been well fretted, but I'd say when it is me making it, I will settle for a B on the "grade vs effort" curve. I don't have the time or money to make it to an A+ on my own work haha!