[Quranic Reflection] : "Joseph; he came to you before with the clear proofs".

[Bucky Ball]

Allah = The Father = Yahweh
The same entity; known in different cultures with different names.

Not really.
The origins of Al'illah (Allah) came from the the crescent phase of the Arabic moon god, whose name was Sin, and was one of the hundreds of gods the Arabs worshipped in the Kabballah, pre-Islam. (It's the reason also that in the Satanic Verses one of the divine daughters of Allah was a moon god).  
He was NOT Yahweh. In fact they were brothers, both from the Babylonian pantheon, and repeatedly, Israel was told to stop worshipping the god Sin, in the OT.  
Islam being "an Abrahamic religion" is true ONLY in the sense that Abraham was a prophet, in both systems, but NOT in the sense that they worshipped the same god.
There is a lot of archeology and scholarship that proves all this.