1. It is now time to review what I have found out since the beginning of my efforts:

... During my holidays in the year 2000, off from work and enjoying a nice time of rest with unusually fine weather in our summer house, I read the book by Thomas Barthel and learned that Easter Island had more than one mystery, not only the famous stone statues but also an undeciphered system of writing. Realizing that in a few years time I was going to retire, I suddenly saw the possibility to continue an active life even after that by trying to decipher these writings! It would be like a gigantic crossword, keeping myself occupied years ahead. So I decided to try it. I would allocate 10 years for it starting at once ...

It took more than 10 years to satisfy my curiosity. I am writing this in January 2018.

An example of what I have read:

Immediately we can perceive a symmetry of a kind, with a rising fish at left and a descending fish at right - 4 days later according to my understanding of the text.

I have assigned the dates after having successfully correlated the glyphs with the right ascension positions of the stars at the time when the Pope Gregory XIII presented his new calendar:

... The Julian calendar day Thursday, 4 October 1582 was followed by the first day of the Gregorian calendar, Friday, 15 October 1582 (the cycle of weekdays was not affected) ...

... July 4 is the 185th day of the year (186th in leap years) in the Gregorian calendar. There are 180 days remaining until the end of the year. The Aphelion, the point in the year when the Earth is farthest from the Sun, occurs around this date ...

The name Wasat means Middle and the Arabs used it for the star δ Gemini.

... Wasat, and Wesat are from Al Wasat, the Middle, i.e. of the constellation; but some have referred this to the position of the star very near to the ecliptic, the central circle ...