A weak shifter is likely caused by more things than a worn shift lever. Typically, the detente plate is also worn, as is the upper bearing. The lower bushing is frequently missing in these cases, too.
To make the shifter safe again, it's almost always necessary to pull the column and replace most of these parts. If you can find someone to weld the shift lever and grind it to the proper size, it will last longer, as the metal used in welding is harder than the original.
Is it a pain to do? Absolutely. But it's worth it.
~Steve
