Source: leon-1364 on eBay.de
This must have been one of the earliest horns built for Hohner. The seller indicated it does not have a serial #.
All the features indicate that it is indeed a Phase 1 model President.
If you want to change how many album pictures per page, use CTRL+ and CTRL- (Command + and Command - if you have a Mac). 80% looks great on my 4K monitor.