Cylinder shaker

Took my 84 Camaro out today and found when I got back the trans has a leak. I can't tell from exactly where. It's not a lot but these things never get better. Someone suggested because it's not that bad to try the stuff from lucas as the seals may be not expanded. Its a summer driver only. I use the GM syncromesh in the trans and was wondering if a thicker or thinner fluid might help? The car is a low mile 29k original car. Thanks for any help...

AMP-D

Spray it down with brake cleaner and see if you can see where the most forward spot is wet. Thats the area its leaking from.