Marble Memorial Company Logo ID?

This one has me stumped. I'm trying to ID the maker of these two marble funerary vases/urns. It is stamped on the base of each "M" in a diamond. I have been unable to locate any resources for a list of makers logos, and Google image search is not helpful either. Does anyone have a clue? The urns stand 9.75" high, lathe-turned. Age unknown. Thank you!

 

I started to search ... it's a tough one for sure.

 

Thanks! Did something happen to Google image search? For a while it was really getting accurate, and you could even crop to zoom in on details. Now it's back to random inaccuracies.

 

I do not know about the zoom features. I assume that is based on your system? I searched images, logos, various combos of terms. I think it's just a tough item to get the info you're looking for.

The next and lengthy "rabbit hole" search is via vintage publications geared to these products.

 

if you bought them locally you might ask the people that sell funerary urns in your area. They probably did not travel far.