Transmission Leak

Hi, after a gearbox replacement of all gaskets, etc. noticed a small leak which may be coming from trans reservoir. The car has been stored for a month waiting for UK registration. I am hoping this is coming from the overfill as you can see the fluid is above the max level. Assume driving it will stop the leak?

Car is a 928 S4 1989 Model

The level may show high at the fluid reservoir when the engine isn't running.

The correct method to check the A/T fluid level is is to heat the transmission fluid to around 80C (175F) ... take a drive to warm things up, and then look at that window in your photo.  The engine must be running with shifter in neutral or park for an accurate level check.  If it is overfilled, use a fluid sucker tool to remove fluid until it is at the proper level.