Transmission Leak 1970 Mach I

I have a 70 Mach I w/ a 351w and a FMX trans. I put it away for winter a couple of months ago and the other day I noticed a fairly large leak. It was dripping from the bellhousing of the trans. Is it the seal on the input shaft? Or is it somthing to do with the torque converter? It is a very slow leak but it does seem constant (not just on shut down of the car) as the car has not been run for a couple of months. Your opinions are appreciated.

What areas could the trans leak from after it has been sitting for some time. Obviously the pan but that is not where the leak is coming from. The lines could be a possibilitly but there good also.

I guess I should replace the seals on the input shaft of the trans. How hard is it to change this seal? Is there any special tools needed? Or should I pull the trans and give it to a shop? It's starting to feel like i'm talking to myself in here LOL