Alex,
I found this document:
https://heritage.canadiana.ca/view/o...9/5194?r=0&s=4
While this programme is dated 3 Jun 43, and there must have been some subsequent changes (ie: QE arrived in Halifax on 3 Sep vice New York on 4 Sep), I believe that it shows the likely Port of Disembarkation for your Great- Grandfather was Clyde.