I think we both totally underestimated the effort required for cloning the J1.5 template into a modern J3 template based on the Gantry framework.
Additionally, during the template migration, 2 newer versions of Joomla were released. This introduced some instability in the process of validating the delivered new template as well as a bit of "moving target" syndrom.
As I wanted to understand the Joomla template architecture and its inner working, I could rely on David sharing his knowledge with me. We did two lengthy Skype sessions for that. David always responded positively to my numerous requests for fixing some very narrow cosmetic detail in the template. The whole process extended on quite a long period of time, but this was ok for me since I was often not available for validating a point or providing some feedback. Neither had I set a target deadline for the project.
In the end, the objective to reproduce my 1.5 template with some improvements, among them responsiveness, is totally fulfilled, and I gained a pretty good understanding of how a Joomla template is structured and customized. Thanks to you, David, thanks for the hard work.
Jean-Pierre Schnyder