I would stand at the position of the chair, hold my palm facing the camera and spotmeter it and tentatively "place" that on Zone VI.

Because foliage is tricky, I would disregard (or interpret) any meter readings off the shrubs. You didn't say, but you obviously ignored them too.

I might have allowed the Upper left corner to fall a bit higher since it would look good on print at VIII. This would favor the shadows.

And I often use 400 speed film at lower EI, so that would have suggested more exposure to me.

So I think I might have given 2/3 to 1 stop more than you gave.