You didn't say what Trico vacuum motor you have so here is info for a 1950 Chevrolet truck.
Trico says it is model SSM-412-2
Pictures with handmade gaskets on ebay (need to make sure the seller is using approved gasket material).
https://www.ebay.com/itm/153900469442Bob at wiperman.com has helped me and many recommend using him to do a rebuild.
A vacuum motor has to seal properly (gaskets, paddle surface, paddle material).
Cleaning, installing paper gaskets and oiling the paddle may be a temporary solution.
It's similar to squirting oil on cylinder walls to make a higher compression reading on the gauge.
If the wiping torque drops off after your work, consider a rebuild.
Carefully checkout the part identified by the red arrow.
I don't know the composition of the rocker but they are known to age-out, wear, corrode or break.
This part is one of the parts used to switch the direction of the wipe.
