Next to the VCF section is the ADSR and AR section, which I've finished now, too:
20150414_231757_5337m
Main Board, ADSR and AR Completed
Jacks and switch still missing, sliders and button installed for testing.
Powering up again, connecting the according ADSR and AR outputs to my oscilloscope and pushing the button shows the following waveforms (after some fine-tuning of the sliders):
20150414_ADSR
Testing ADSR Signal
20150414_AR
Testing AR Signal
This looks pretty good, I think.