The marks shown here are not related to porcelain or ceramics, but to enamelware. I have added them here as some people have used them as a reference or claimed that they are associated with companies such as Hinrich & Co., just to name one. This is, of course, complete nonsense.

M250201a
"AUSTRIA" sitting above a two-headed eagle which is placed above "H & C.".

M250201b
An eagle sitting in a pan or tray of sorts, set above "AUSTRIA".