[bojan]

Success!
A few drops of acetone helped to soften the glue.
Now I am in business!

EDIT:
All done.. but the results from last night were not quite what I hoped for..

So I added this "springy" bit, cut out from black material used for plastic folders - I find it very useful for variety of applications.. (like hard paper, but water resistant)
The ends of the spokes (10mm) are folded back and now they act as a gentle springs, positioned exactly opposite of mirror seats, deeper in the tube (made of bits of kapton tape), so the mirror is held in position at three points, 120° apart... hopefully with no stress that might cause the deformation.

we'll see the results of all this hassle tonight..