Dear list members,

I've been asked to provide a manuscript image of the ādigayatrī mantra from the ṛgveda that shows the accents. I can find images of accented Rgvedas online but they all have the accents anudatta and svarita. None I could find had the double svarita accent. All svarita accents were marked with the single svarita accent mark , a single vertical line.

But if you look at this video comparing the Shringeri, Kanchi and Varanasi styles of reciting the ādigayatrī mantra, 
https://www.youtube.com/watch?v=mQ2nYFnMiQk

At 1:37 it shows that the  ādigayatrī  mantra is pronounced with some double svarita accents. 

See below:

1) Do ṛgveda manuscripts (or any vedic manuscripts) exist that have the double svarita marked.  I had assumed this was the case because double svarita is in the  unicode vedic extensions block.