Hi Martin,
thanks for sharing this kit.
Back in 2013 I built and performed a number of activation with a homebrew Multiband vertical. It performed well, but nowadays I rather prefer to use my multiband EFHW.
My vertical also had a coil for 30m and 40m and was a true quarter wave for 20m.
To improve performance a bit, my coil wasn’t in the base but elevated about 2 m in the middle of the aerial. I also used a single elevated radial to fine tune SWR and was easy to set.
You can see it here:
And the final version fully described here (sorry in spanish…):
http://hamtennas.com/docs/Antenas_HF-III.pdf
73 de Ignacio