I DID IT!!
I left out the epub2 for now, for simplicity:
<div class="wrap">
<figure>
<svg xmlns="http://www.w3.org/2000/svg" height="100%" width="100%" preserveAspectRatio="xMidYMid meet" version="1.1" viewBox="0 0 600 900" xmlns:xlink="http://www.w3.org/1999/xlink"><image width="600" height="900" xlink:href="../Images/7_Hitlersigned.jpg"/></svg>
</figure>
</div>
Using ibooks for a quick check, and it's working!
Will be checking other reader apps and Kindle (less likely to work?)
Now I just have to add the caption somehow...
THANK YOU!!