Technical New and confused by a loose drum

That looks correct as far as the lugnut. What's wrong in my opinion is the length of the stud shoulder coming through that far. When swedged correctly in place the shoulder does not stand that proud of drum face. Could also be just the wrong studs even though they fit the hub hole and shank threads. I'd suspect the clamp force on the wheel is not correct.

 

I think your correct but my only sticking point is why did it just recently become a problem?

 

Yep that’s the problem I rigged it up with a washer so the clamps the wheel face not the bevel and everything is tight.

 

Yes wrong studs ,when I have replaced on A , 40 hub , I went threw Dorman book .
Grind weld down with care , knock all studs out ,
Found correct size for hole Now in hub
Spline to correct hole size .
Cut 1/4 off one side of Flange on stud to clear taper near bearing,
Press in ,
then drilled drum with Some times , Fraction , metric , or letter size slide drum back On
Know drum can be removed with out
Removing Hub ,

 

What Anthony circled looks like the shoulder that would be swaged into the drum
Model A studs are swaged to hold the drum on the hub..the whole drum, stud, hub assembly together.
Welding the back side of the stud on the hub is a no-no and should have never been done. It may hold the stud on but does not affix the drum to the stud.
I am sorry that you have this situation....the threads don't look all that good either and almost like the wrong stud was installed and cut to length.
Stud replacement with the proper ones, swaged on, is what really should happen....
I don't know what your plan is for the car....are you going to keep it stock?

 

https://www.snydersantiqueauto.com/searchm.htm?type=merged&sterm=&searcht=hub+studs

https://www.snydersantiqueauto.com/searchm.htm?type=merged&sterm=&searcht=A-1109-T

Also, I don't know where you are located. You might be able to find a Model A Ford Club of America chapter club close by and have some folks with some tribal knowledge to assist you...just a suggestion