Hey Billy,
hey Barry
Thank you very much for your feedback. Due to a heavy workload at the office, I only got round to following up your comments today.
Long story short: the phaser is now working without any problems.
As I wasn’t quite sure myself whether R20 might not be a 15k resistor after all, I quickly desoldered it.
With better lighting, however, you can see that the 4th multiplier band is red after all.

The measurement also gave a proper result of 14.93k.

As Barry suggested, I then re-flowed the six pads of the connection (as well as a few others for the sake of good order).
The result: the phaser works!
Thanks again for your feedback and your help!
Do I have to mark the title of the post as ‘solved’?
Best regards
Fabian
Ps: When reviewing the instructions again, I noticed the following error at the bottom of page 2: ‘D5 requres a Yellow or clear White LED’. In my opinion, this should not be D5, but D4.
