Rongorongo script vs Indus Valley script

Indus Script and Rongorongo have about a dozen identical signs and both use a boustrophedon (alternating in direction) writing direction.
They are far from identical.

Go to Sue Sullivan's blogs on Quora to see what interpretations I've come up with as far as sign lists and deciphered, translated texts.

Indus script has turned out to be a semi-syllabary writing system with fewer than a hundred basic signs, but many combination signs and variants of existing forms. I cracked it in 2010 by comparing it with Brahmi script and the few known signs of Linear Elamite (there's a bilingual Akkadian/Elamite inscription of the monument known as the Table au Lion in the Louvre Museun in Paris). The languages encoded are archaic Prakrit and Sanskrit. Most of the inscriptions on the seals are personal or place names and addresses, with a few words such as na-ma-na (greetings). Many of these personal names are still in use in India.
I've published a book titled Indus Script Dictionary with over 2000 photos of Indus seals in translation.
After I began posting about Indus Script online, a lady from Canada began encouraging me to work on Rongorongo script. She sent me books about Rapa Nui and links to online glossaries of the Rapa Nui language, as well as a Tuamotuan dictionary by Stimson and Marshall.
I came up with a Rongorongo sign list using the rebus method and the known sound values of the Indus signs.
The inscriptions on most of the Rongorongo plates were tales of the early settlement of the Rapa Nui people, in particular Hotu Matu'a, a noble probably from Hiva Oa in the Marquesas. The language was an archaic form of Rapa Nui with lots of Tuamotuan words. One brief inscription on the end of an oar turned out to be a boat sign, giving the name and description of the owner, and describing his boat as 'this leaking thing.'