Just a thought if the new one is the same. Place the old plug on a 2x4 flat, the take a ball peen hammer and place the ball against plug. Take another hammer and smack the ball peen into the plug. It will cup it slightly if not hit to hard.
Place in hole if it will fit, then use something to flatten it back out
Do wear safety glasses
Sorry I got ya off of where you needed to go at first