The RCA auto patch is the first RCA patch. Heard once only 300 produced. So that is the toughie. Yours looks like an original, but there are fakes, the most noticeable of which is on a yellow colored material.
The RCA Single-Six patch was the 2nd patch... probably 1976/1978. Not common, but you see more of those than the auto patch for sure.
Then the silver eagle patch is the Australian patch. There are a bunch of fakes of that. The genuine article does not have a glue back. It is probably just as tough to come by as the RCA auto patch, probably since it was meant for Australia.
Chet15