Peteb,
It's interesting that you suggest it was a travelling journal. I don't know how long that idea has been around, or versions of it, but although it seems logical (first associated with a Franciscan and then said to have come to Prague in the possession of an anonymous 'traveller'/messenger), I found that my saying I thought it a compilation made for a travelling profession didn't meet cries of joyous recognition in 2010.
Maybe more people think the same now, which would be nice.
Mapping the content's range: interesting problem because while mapping always looks good it's sometimes like advertising; you have to know enough already to recognise what is left out - and why.
e.g. a map showing all the Roman baths in Armenia would really only tell you that someone supposes the 'bathy-' section's pictures are meant literally and not metaphorically or allegorically, and that their theory is about Roman-era Armenia.