SLAYER "Show No Mercy" vintage backpatch, 1984. It comes from a guy's battle-jacket made in 1984.
There's a slight misprint, or overprint to better say, on the left hand side of the BP: the next design was set to close on the fabric roll and/or the patch cut too tight, as it often happened.
Apart from that, it's in a very good state, as shown on picture - there's just a slightly rusty tiny hole on top middle due to the BP having been pinned to a wall before being sewn.