I'm not sure exactly what you're counting. The Norman White cylinder, has all the standard threaded holes and thru bolt holes - total of 10 - same as a standard Norton cylinder. And then it has an additional 4 holes for the recessed thru bolts. Those 4 "Commando" type thru bolts, are positioned so they go thru all the fins, thru the standard cylinder base holes and would thread into the cases. Obviously you can't use the standard studs in the cases, if you use the thru bolts.
I've tried it this cylinder on my cases and with a head. No issues whatsoever.
If using the Commando type thru bolts, you are correct that the bolts would be visible and not stock looking. But there's literally nothing "stock" about the Norton I'm building. It's a 650ss motor with this Norman White cylinder and going into a Ray Petty roadster frame. I'm definitely not going for a stock set up on this build. It's all special, special brakes, GP carbs, clip ons, rear sets, swept back Dunstall exhaust, oil tank & gas tank are alloy and made by Lyta - special for the frame kit that Ray Petty sold.
Maybe the photo of the cylinder is somehow deceiving?