Rusty,
Not wishing to get into a pissing contest, all I can say is that Wal Winfer, a personal friend who has pored over more Jeffery records than we will in our lifetimes, has concluded that Turner was his major rifle finisher. For example, from one page of Jeffery's 1907/8 records, Wal found that Turner supplied 11 rifles in the Serial number range #18901-#18911.

You have also got to make a distinction between who supplied the parts (actions, barrels, furniture, sights etc.), and who did the finishing. Sometimes it may well have been the action supplier, but could equally have been someone else.

This does not exclude Leonard as a supplier or finisher, and perhaps at other times he may have taken precedence over Turner?

Whether the finisher bought the Krupp barrels in directly, or Jeffery did, and passed them on to be actioned and finished is a matter of conjecture, but Krupp is listed as the barrel supplier in a lot of Jeffery's ledger entries.

As you know, A. Hollis was an Indian based retailer, and seemingly has no direct connection with Jeffery. Perhaps he operated on the Jeffery business model, but I'm not sure what the relevence is here to the Jeffery "debate"?