I probably shouldn't admit to this as I suspect the stops on the lower yoke are 'sacrificial' . . .
When I broke a steering stop off the bottom yoke, I cut both sides flush, drilled 8mm holes and bolted ss 8mm setscrews through the bottom yoke.
Then put plastic caps on the heads to soften any impact with the steel stop on the steering head.
It looks OK and I haven't restricted the steering lock (careful measuring

).
I'll try not to drop the bike again
I could go and take pictures if anyone is interested.
Bob.