they can be repaired to some extent,the sloppyness in the handle can be repaired by stretching the springs out,they can get compressed over time.
the buttons are a diff matter,they can be replaced but pretty much only as a whole board, unplug and replug in new one.
I have rebuilt a few ,in this matter taking a broken one and one with bad buttons and combining the two. if you are really good and well equiped for the task the buttons can be replaced seperatly but that takes real electronics skill. krusty is right though you might get a long way with a good cleaning.