There were several methods to apply the EGA to the Pocket of the Utility / Field uniform. In my day we used the Iron on and we called them "Camies" or "Utilities". In years prior they were made out of a solid green material (HBT or sateen).
I have found several items that were used over the Years.
The strangest one (I didn't even know it existed) is a block for the HBT Uniform (WWII - Korea time period. this cam to me as a surprise with an eBay purchase a few months ago. I pick up some a lot of Marine pins and the stamp type block was in there. from the pictures that were posted, I didn't even notice that it was an EGA. the others items are a brass stencil from the late 50's early 1960s. the others are various Iron on versions