Thank you so much for your comprehensive reply. much much appreciated my friend.
I also manage to only find the 5016A from only watch as the only other Steel, blue dial ,in grand complication. Another steel with grand complication is the 1518 perp cal chrono from the 50s.
Its very interesting to learn and make new discoveries in our horological journey. Specially in this very friendly community. Thanks again for responding in such detail.
And to your final question, yes its my watch. Got it june from NY auction.