I have a medium grey sharkskin suit coming in from Rubinacci. Lesser Lumb's Golden Bale. Awesome stuff.
To be clear, sharkskin is just form of worsted wool. It's just a different weave pattern, like herringbone or twill. I like it because it adds some color variegation without imposing a distinct pattern.
I'm quite enamored with them at the present. I have to say though, when you look up close, the finishing is far from immaculate. A lot of polish streaks and splotches. Intrinsic to a hand-finished shoe, I suppose.
Lesser makes a fantastic sharkskin.
Sharkskin is not an inherently shiny fabric. The English makers tend to make a very traditional, dry sharkskin.
It's just a particular weave pattern, mixing two colors of yarns. No impact on durability.
I'm not sure if there is an exact match in RTW. Most of the time, you will see more broguing (up the throat and around the topline), as in the G&G example posted.
The RTW balmorals I've seen all have back seams, too.
Still, not a hard design to copy through a simple MTO program.