That is definitely what BSA used prior to 1966. It's also what was used on the A65 Lightning Rocket Clubman.
I am working on parts for a Lightning Rocket Clubman replica, and that is the top yoke I am using.
Also, I am moving the speedometer and tachometer to a plate that is mounted to the top yoke using the two chrome bolts that hold the tops of the fork stanchions in place...similar to how the gauges on Gold Stars were mounted.
This places the gauges over the headlight, instead of doing it the clumsy way BSA did, mounted them on top of the handlebar clamps, 1966-1970.
You may have to modify the fork stop (also known as the lower steering damper anchoring plate) to cut the distance
of "full fork lock-to-lock" to a shorter swinging distance to prevent the handlebars from hitting the tank, especially if you have the big FOUR-GALLON tank.