(...) Meanwhile I explored a little of the heart anatomy
In your model, the right Coronary artery arises from the anterior aortic sinus and the left Coronary from the left posterior aortic sinus
The left mains stem lies between the left auricle and pulomonary trunk
In Your model it looks like left main lies drilling through the left auricle
The right coronary should arise from the anterior aortic sinus (Location of mouse pointer)

Thank you very much for the corrections and sorry for the delay.
I adjusted it.
It will be updated online tonight.