Bear with me, I thought I could figure this out.....
When I opened NA on my beta EOC server I saw my Orion's but no maps. I then kind of remembered taht they had to be imported into EOC so I looked on the NA toolbar but could nto find anything. I then dug into the "C:\Program Files\SolarWinds\EOC\Network Atlas" folder and found the ImportMapBatch.exe application however no matter what I tried it would not log into the Orion's (my Orion's are all 9.5.1).
I then dug around on the Solarwinds site and downloaded the OrionToEOCMapConverter.zip file and installed it on the server but when I click on the link it gives an error about not connecting.
You are right, OrionToEOCMapConverter is the tool you need, but there is a new version which works with EOC 1.3 Beta. I'll send it to you by email.