There is a book "Les Ferrari au cinema" by Philippe Ramlot. From the title it is obvious that the book is in French. Since I essentially know no French, I cannot evaluate the book. I mention it because maybe someone can.
So where is 250 GT LWB TdF Competizione #1399 GT today? It had no race history with no info on the net other than being owned by French actor Christian Marquand who died in the year 2000.
Several owners after Marquand. Badly crashed and rolled, never repaired. Dismantled wreck without engine in storage on a french scrapyard since 50 years. Marcel Massini
I’ve owned the book for a long time. I bought it as a (very) occasional reference. In fact, I’d forgotten I have it until I read your post. I neither read nor speak French but my wife does, in a rudimentary way, and she enjoys translating when I ask her to. I wouldn’t call it a “must have” book for most Ferrari enthusiasts. I don’t think it’s achieved collector status so I imagine it can be purchased fairly cheaply.