440 Purple Cam rust spot is it ok?

It was an old .509 I think with a quick measurement. Still has purple paint by the gear.. I do have the lifters saved in order. I was trying to reuse as much as I could on this rebuild but will likely use a cam recommended earlier a comp cams 683801 .467/.494 lift with 222/234 @.050 duration. Thanks for the advice to you all!