Once the first coat of paint on the optical-tube had cured, I flocked the inside...
Later, I had painted the tube again, as the first painting had flaws.
The retaining-ring for the doublet blackened, and dulled, where required...
The lens-cell itself was not blackened, no need, but certain areas were dulled just in case...
The lens-cell, with the doublet installed and retained, completed...
I've yet to blacken the edges of the doublet. That will come later after I'm done testing for the spacers.