'Evenest' vs 'most even' word usage and its history

According to dictionary.com, the comparative form is evener, which would make the superlative form evenest.

It is rare to encounter this in written or spoken form. I believe the reason for this is because even is as comparative as perfect is nowadays. In the past, one would make comparisons, evener and more perfect. Current usage tends to even as perfectly so and perfect as perfectly so without the need or ability to compare.

Here are a couple of examples using evener from dictionary.com.

The smoother and evener all brewers' casks are made on their inside the better, as they are thereby the more easily cleaned.

The small pieces, therefore, absorb the heat more evenly, and this gives an evener action of the rennet.