Next time you have the pan off, take note of the markings on the dipstick. The 'full' line on it is the same level as the pan mounting pad. If you're over filling the trans it is very hard to control leaks. You will also find it hard to control if the car is not driven regularly. The fluid in your converter siphons back and overfills the pan, then the leaks start again, a regular fireup to re-fill the converter will help.....have you looked at the Moroso silicone pan gasket?
If you discover your problem is not the pan gasket, then place a large sheet of cardboard under the trans the next time you park the car and then note where the drips land. The dipstick o-ring, the shifter linkage seal and speedo seal are all likely culprits positioned in different places on the trans.