Patricia,
Your additional tech info certanly opened my eyes, you have been caravanning a lot longer than myself, can imagen the shock what happened to you after all your travels.
If the explanation Cris has given is correct it is certainly a eye opener.
Two years agao i changed from a inline stabilizer to a alko 1300, which included alko towball as part of the kit.
Main reason I found that putting the inlin stabilizer locking pin down was getting very hard, Found the alko 1300 a lot easier to operate.Extra bonus is having a grease free towball.
I have seen on some sites people are still towing with the standard tow ball with alko stabilizers, and not with the correct alko towball which gives the alko towing hitch more
height clearance over the ball, expecialy when during a turning manoeuvre.
Roy