This is building up to be another much appreciated wedding gift
I think the groom has a stronger jaw line than suggested by your pastel. If you consider the posterior border of the lower jaw, from the bottom of the ear down to the angle (where it turns horizontally forwards), you'll find this is longer in the reference than in your pastel preliminary. This part (the angle) is covered in shadow, but blow it up and compare and you'll see what I'm referring to.
The gentleman's ear has a distinctive characteristic which we mustn't ignore - the helix (the outer curved part), as it descends along the poster margin, is bending backwards to flatten towards the skull. This is not only making the Anti-helix (the inner curved part) prominent, when seen in this particular perspective gives the ear a pointy look - which compliments his nose, IMHO!
Another thing we mustn't ignore is his almost Monalisa-esque smile
Those soft mounds of flesh at the corners of his mouth are creating natural sfumato
like shadows in that region, acting as a nice contrast to his general ruggedness.
I'd also like to draw your attention to the shape of the skull above the eyebrow ridge, esp the part of the forehead along its right margin (our right).
You're on to a promising start - Good luck!