Help! Looking for samples of Mammoth Powder

I am starting to work on an article on the history and developement of Mammoth Powder. This was a large, compress pellet of BLACK POWDER. It dates from about 1864 to the 1880’s when smokeless powders replaced it.
I would like to correspond with anyone who has a sample of 3/4", 1", & 1 1/2" powders for the 35, 50 and 100 ton English Cannons. These are square examples of pressed gunpowder.
Also, with anyone who has a sample of American Mammoth powder (hexagon in shape with 1 or more holes through the grain). Again, these are black powder and NOT smokeless powder. These were compressed powder grains which are suprisingly heavy for their size.
If you have a sample, I would like to get some GOOD photographs of these for the article. There is nothing drier than an article without some good photo’s.
I do have an example of British Brown Hexagon powder, so don’t require that one.

Any help on this would be appreciated. This is NOT a solititation to buy these. I only want photo’s and weights for my article.


Will Adye-White