Had the same advice from the Nice Middle aged Fella I got my car from.
"Spark plugs were replaced in the last 10000km (receipt in folder) if you ever do it again
use the same ones - trust me!! - Autolite Double Platinum APP3924"
Supposed to last 80,000kms !!!
Within 10,000kms of purchase, it started to misfire but only on idle. (so less than 20,000kms all up)
NGK BKR6EYA coppers have gone in twice now (every 10,000ks and Never a Problem.)