Drew, do you have any information on the powder described as "Blended Amberite" ?
I have seen references to its use in making heavy loads for wildfowling guns - notably for thin brass case chamberless guns. Some texts with tables of loads and powder charges list data for the standard shot charge with black powder, bulk and condensed nitro but I have never seen any reference to "blended" amberite contined therein.
Also some tables give similar powder weight for Schultze and Amberite, but others show the latter powder at a slightly lower weight.

So was "blended" referring to a factory labelled product or was it a homeloader's concoction?