E-body Wiper Arm Part

Is there a place that has the wiper arm part the wiper blade attaches to? I have no idea what it would be called (the splined stud). someone replaced the one on my car with a bolt and I would like to correct it and the rest of my arm is mint. If not I will keep an eye out for cheap ones at swaps and pirate that part off of it.

sad to say, if you can't live with the bolt, it's time to replace the arm.

I have lived with it for 18 years but as I fix/improve things over time, I am getting more and more nitpicky and the bolt sticks up just enough more to scratch my newly painted T/A hood : (. Best case would be to find a trashed arm for cheap that has that part on it still. I have a descent complete arm but my original is in better shape other than that part being MIA.

is there any chance you could get some good measurements of the missing pin using dial or digital calipers ?
i have some miscellaneous arms laying around i could chop the end off and send it to you, if the pin will work.
won't cost ya a cent.
let me know.

I could and will. I would hate for you to wreck a good part though, if they are in good shape.

these are stuff i have had laying around forever, and i'm "brooming out" [as DoC FLaPpeRGasS would say] my excess parts inventory i'll never use.
i'm thinking these are mid 70's chrysler arms, as i have had a few over the years that have been scrapped.
i'm guessing the pin is the same. hopefully.