Good thread this.

Merlin Pete – Yes, there were 6000-size bracket props. They were fitted to the early Beaufighters and all Hercules engines had the 6000/SBAC60 prop shaft.

Anon.

Yes, the 6000 series bracket prop is mentioned in the lists I have, but the question mark is over the shaft size and shank size in that instance. I assume it is as you say, a No6 shaft, and probably an E shank, making it similar to a 43-E-60.
Hercules had three shaft types, tapered, No5 and No6, but I think the Beau would have been a No6 from the start in August 1940.

Pete