Laksen-
I did solve this, and put the updated code on my website. The solution required three new parts of code:
1.) modelview glScalef with proportions prior to drawQuads in renderbackface
2.) modelview glScalef(1,1,1) prior to drawQuads in raycast
3.) glTranslatef adjustment for proportions in DisplayGL (so that the center of the rotation axis is the center of the volume).
Regarding the second problem, then shouldn't it be reciprocal? And are you doing the call to glScalef in modelview matrix mode?