The mirror is now parabolized to better than 1/18-wave RMS, so we are assembling the telescope to star-test it prior aluminizing the mirror. If and when everything looks OK through the scope we will send the mirror to be aluminized.
We came up with this mirror holder out of ca 20mm thick oak board. There are three M8 screws that support the mirror cell. Springs push it upwards, and the wing-nuts used for collimation pull down. It's all going to be attached to the wooden tube by three L-brackets.