How big of a strength imbalance is that my overhead press max is 58kg whilst my bench press max is 75kg?
Its fine.
You should be more focused on getting your maxes up than worrying about any imbalances between them.
Hardly any.
Also, imbalances can sometimes, at least in part be superficial, the actual difference (as opposed to the demonstrable difference) is possibly attributable to a difference in technique, set-up, lack of practice, psychological blocks etc
Since you’re following a Jim Wendler program, consider this bit of wisdom shared by Jim.
If you squatted 1000lbs, benched 1000lbs and deadlifted 1000lbs, the only thing that could possibly make you feel better about being so unbalanced would be taking solace in the fact that you’re the strongest human on the planet.
Be a freak.
Get your max bench to 150kg or ohp to 100kg then reevaluate imbalances.