A very nice shot indeed, especially for sunny-16.
But the details given [1/45 @ F4] is what bothers me about the sunny-16 rule. If that scene is rendered accurately, I would assess that light as "heavy overcast" which according to Fred Parker's "The Ultimate Exposure Computer" would rate an EV of 12. With ISO 100 film, that would equate to 1/15 @ F16 or their equivalent. For ISO 400 film, that would be adjusted to 1/60 @ F16, which is at least 3 stops under the exposure taken [1/45 @ F4].
So I would have severely underexposed this shot, using my sunny-16 "technique", which would have been extremely frustrating. That is why I am always looking for small light meters that I can use as backup, until I get this thing figured out.
Is B&W so forgiving that a 2 or 3 stop underexposure is tolerated or recoverable? Even if that were so, I would not know it was underexposed until I developed the film, and I would have lost any chance to recover some of the exposure during negative development. So my recovery would have to be done entirely in PS or other s/w tool.