Sorry for the late reply Glenn.
A bit heat (careful!) from a tool (handheld heating fan) helps to weaken the glue.
The cap of a bottle glued with some strong double-sided scotch guard attached to the cover and : Voila!
Another guy opened his FR64s that way already- i will do so as soon as i found an experienced bowing-workshop for our project:
Overhaul, new cables,
AND! built and bow a longer (12`) arm for the FR64s with precise FR66s measurements.
We are discussing to built this armtube for the FR64s in the German aaa-forum
(analogue audo association) i`m the threadstarter.
Sorry, but its in german:
http://www.analog-forum.de/wbboard/index.php?page=Thread&threadID=73858
cheers,
gourmet