42RH advice needed

Thank you for the speedy and helpful replies. It did smell a bit...
Kickdown linkage is rod all the way. Is it possible that this wasn't adjusted right when the transmission was installed and has caused the issue or more likely that the transmission was tired as purchased? The car has been driven less than 100 miles since it was installed. I got a very good deal on it so I was expecting to have to do a rebuild.
I was hoping to run the transmission as is to test overdrive and lockup operation before a rebuild but it's looking as if it might not last too long. It will be a week or two before I can get it in the workshop and wire up the switches as there is another project in there I'm doing with my son. Nearly finished with that one - just need to fit seat belts. Starting from scratch as it's from 1959 and doesn't have any mounts for them.