S&W model 459 issues?

[Wesco]

just wondering if anybody knows any information on the old model 459 smith and wesson 9mm. I purchased it cheap from a buddy, when I fire it the manual thumb safety slips back into safe position between every shot so that you have to reset the manual thumb safety to hot before you can actually fire a round preventing the weapon from going into semi auto. after doing some research it seems that this is obviously not the way it was intended to be.

if anybody has some helpful information that might help me solve this issue or a good contact number for smith and wesson that would be awesome

 

[SGB]

Sounds like your Safety Lever Plunger/Plunger Spring may be broken.

 

[Wesco]

Do you think that is something I can replace myself? Or something I should send it in for