There was a previous thread which could be of some help "Who do you purchase from for your 400" (https://www.ferrarichat.com/forum/threads/who-do-you-purchase-from-for-your-400.590400/#post-146351460) In addition to the shops mentioned in this thread, I am quite happy with Coppola Old Timer (based in Napoli).
What parts do you need. Gerry at exoticautospares.com in Sydney has a bit of gear not listed on the website. Shoot him an email, and try your luck Sent from my iPad using FerrariChat.com mobile app