Bakers Pride Y602(refurbished)

So Bakers Pride Y602 users. Looking at this pic below, what marker would you use. Im trying to hit 575-600. My old oven thermostat, was always off and with these new ovens, i dont know which marker to use. I have been playing with it, thinking the rivet is my marker. So this is a refurbished oven & the seller(company) i purchased from, i had to call as the backwall where they painted is now peeling & they claim that the heat resistant paint they typically use, they cant get anymore because of some type of regulations. Has anyone ever heard of or seen this situation???