'78 F150 4x4 400

I've been leaking tranny fluid since I got it 4 months ago and have been adding 1/2 qt fluid every week or two and keeping an eye on it. It would drip a few spots when sitting but was always pan-wet after driving. I kept wiping it away and watching. It seems to be coming from the cover plate on the front of the bell housing.

So, anyway I figured front seal...I'll eventually have to rebuild and just want to keep it running for now. I put in 1/2 qt Lucas trans fix which seemed to stop the leak for now. However, the shifting is very very soft.

I've confirmed that I at least have 2nd & 3rd gear. I'm only getting one shift from a stop. I can manually shift the gear lever into 2 and get no shift that I can tell from a stop then shift to "D" and it shifts. Trying to manually shift into low (or 1) seems no diff than "2". In fact, I don't even feel that "click" detent on the shift column when trying to manually put it in low.

Before adding the Magic Lucas Tonic, I could feel 3 distinct shifts. First gear was fairly quick from a stop (at maybe 10 mph?) but it there. Now I don't feel anything at all.

Is it possible it's starting in 2nd? Or is the shift from 1st to 2nd just more mushy and unnoticeable with the Lucas Goo?

Thanks for any input!