I apologize for so many posts having issues with phone.
Of the 3 1953’s I’ve owned I don’t believe they had the stud. I believe the stud was for the dual spring fork style. I’ve had several Monarks with original paint that had mismatched parts on them . For example, I had another bike just like the Gumby green one pictured, I think it was a 1950, ( with the big deep fenders) only problem is, it had what looked like a 49’ fender on the rear, same paint, pinstripes and patina. After inquiring about this, several collectors told me that this did occur due to someone at factory installing incorrect part.
It appears that your frame is pre 53’