Advise on Transmission issue please

[c5_nc]

Just brought home my 68 Charger 440/727. It left mechanics place to body shop. Body shop reported trans fluid leak, showed me 3 spots around garage with stains. We checked there before I left with car running. It was in acceptable range, about 75% the way between Lowest and Highest level, so just under high mark. I thought maybe overfilled (?) and left with it.

About 20 miles later transmission started slipping. Running ~55mph you could give it gas it would just rev up. Pulled over in parking lot and working fine again.

Drove another 5 miles home, starting slipping really bad again at slower speeds.

With car off checked fluid level again. Dipstick dry. Noticed it was a Ford dipstick at this time. Tube looks like correct mopar part. Started up car to check level and it was in acceptable range, maybe slightly down. Say half way between low and full this time. Talked to mechanic they said low fluid level (even slightly slow) could cause these problems. Unsure of correct amount I just added a quart. Have just drove it around short distances and it is fine. Leaking again though. From engine bay looks like from around where tube enters trans (or could be leaking down to that spot). Anyways it looks like that is the area of leak.

Advise?

Likely leak sources?

Have not been able to find a new dipstick yet without ordering whole setup online. Autozone has was looks like tube/stick generic part, looks same size and shape for $15. Any ideas on where to find?

Does the dipstick being dry when I stoped point to anything?

[John_Kunkel]

With the incorrect dipstick you'll never know the correct fluid level but one possible explanation of the varying level is checking it in Park instead of Neutral. In Park the fluid level will be considerably higher than in Neutral especially if it's checked shortly after starting cold (or if checking it with the engine off). Engine must be running for an accurate check.

There are a half dozen common leakage points on the TF, the only to find the leak source is to thoroughly clean the outside and then trace from the puddle on the floor upwards to the source(s).

Only time will tell if major damage occured from running with low fluid.

[AmadeusCharger500]

Doubt you're losing that much oil in leakage to make a difference on the stick. Probably the dipstick fault, and variable methods of checking.
I think you have to go to specialty shop or mopar dealer for correct one, but call around.