@Kinesis No need to feel bad - I'm helping here voluntary :-)
I don't think you need to upload your code. If somebody has questions he/she can ask.

Hey Joel

Thanks the code lines:
QGraphicsScene* scene = new QGraphicsScene(this);
ui->GVpreview->setScene(scene);

fixed the issue as I don't know how to do the scene view bit in the form editor.

Hi and welcome
Many ways to do this, but here is my suggestion.

Add a signal to your graphicview class

signals: void MWheelActivated(bool ZoomIn);

and hook it up to a slot in your mainwindow with the connect function.
http://doc.qt.io/qt-5.5/signalsandslots.html

then in GraphicsView::wheelEvent(QWheelEvent *e)
you
emit MWheelActivated ( (e->delta() > 0));
and No zooming here!

Then in mainwindow slot

mainwindow:: MWheelActivated ( bool ZoomIn ) { if ( ZoomIn ) { view1->zoomIn ( 6 ); view2->zoomIn ( 6 ); } else { view1->zoomOut ( 6 ); view2->zoomOut ( 6 ); } }

Hope it helps.