During the demo I had the C7's ended up on a pair of Foundation metal stands - there is even a brochure for them in the factory packaging. They have a metal framework not unlike the stands you illustrate. They don't have the "feet" that are shown above, and the spikes were welded onto the bottom corners. The somewhat ratty used pair that we demoed with weren't going to be all that cheap, and new ones were more than I wanted to spend. No real adjustments for the spikes, and I wanted to avoid those anyway due to the hardwood floor here.There is a UK company called "Something Solid" that makes custom open frame stands for Harbeth speakers. I can't find out much on them, though I've seen their stands in photos. This one is for the Monitor 30. Not the last word in aesthetics but they're probably closest to what the speakers actually want to be sitting on. Also, looks like something a local craftsman could make for you.
When I first got my SHL-5s I made stands similar to this from a pair of old metal frame end tables. They worked out well and I used them for long time.
They don't seem to be made anymore - a search for Foundation stands for Harbeth shows the stands for the M40 as metal, but ones for the C7 are a four post model. Planet of Sound advertises them. https://www.planetofsoundonline.com/collections/speaker-stands
I'm just happy to be done with all this. :biggrin: