I've added a larger picture which might help.
There's only the one line connected to this part. A small diaphram (approx 1.5") and a plug in the opposite end of where it is connected. If it is a pressure regulator, I was wondering if the slight leak is normal. Although, I would think it would stop when the set pressure was reached.
Another off topic question regarding this truck...
It has a Spicer 3152A 5 speed and I cannot locate the filler plug. Forty plus years of grime to scrape off to have a good look but I sure didn't notice one.
Dan
