The ice cream cone shaped extensions on Ambrosio adjustable stems are great lookers.
Unfortunately, the aluminum is soft and the tolerances tight.
So the extension is easily nicked and the notches easily deformed when tightened a bit too much.
Consequent removal of the extension, or even slight movement, is a B*%^&.
I passed a fine file over mine, on all the flat surfaces.
It helped only a little.
A wooden mallet helped more. Then much more file work, once removed.
Amir Avitzur
R"G Israel.