I sold a FI 380 last year. It was like new and I just never used it much. Had a nasty habit of the hammer biting the web of my hand. So I said goodby and sold it cheap.
I never had any problems with it in the sense of broken parts, so I don't know any parts supplier. The pistol is very ammo specific, very fussy, likes ball ammo. and will act up on modern hollowpoint ammo. I am sure Brownalls or others can replace springs and maybe direct you to someone who sells parts.
This pistol was made by Star and was the model "D", sold by several different companies. Value is in the $250-300 range
You can get parts at www.gun-parts.com/index.html