Vintage IWC (?) watch - what is genuine in it?

Hello everybody, 
My mother gave me this watch, wery old, it comes from the family. It is strange, based on the movement serial No. (387783 -  what a symmetry ?!) it would be a cal. 53 dated 1907 (pocket watch movement), but the case diameter is only about 32 mm. Also, neither the case is IWC marked, nor the crown. Please, can someone tell me whether this is a genuine IWC or just an old fake? 
Thank you
.

Don’t invest

Tonny B is right : nothing from IWC.
The movement nr. 387786 refers to cal. 53 in the IWC ledger , made in 1907.
This movement has nothing to do with cal. 53 and in 1907 IWC did not make a wrist watch with a cal. 53. The first wrist watch had cal. 64.
Regards,
Adrian,
(alwaysiwc).