1TX ignition switch tightens

[Vilike]

Hi guys.

My old 1TX has about 149500 km-s in its meter. It runs very good. But the ignition switch is slowly dying. It tightens when the key is turning, but the key is a bit too loose when i take it in or pulling it out. The key is torn too. What is the solution ? Can i rebuild it or should i buy a new one ? What about the worn key ?
Thanks !