Lots original - just none Breitling original
To my knowledge, Breitling never employed a double caseback - so its a telltale sign of an imposter
Other things strike me as strange:
1. Breitling logo on the bridge is of later (post 50s) design, but logo on the dial is script (40s design).
2. Hands too small for the dial
3. Dial is just too busy to be read easily and lacks the asthetic quality of a real Breitling design
4. Sub dial diameters disproportionately large for the size of the dial
5. Front rim of case appears a bit too wide to me
I'm sure one of our experts will be able to tell you more, but the foregoing is my feelings about the piece.