Speaker stand makers - Tannoy Turnberry

Skylan might be able to help you they do Harbeth stands. Timbernation is another.

You could try sourcing a local carpenter. I've had great luck doing that. Taking a look at them, they could use something like what Kenrick Sound uses for their big JBL models: an X-shaped base that supports at all corners while crossing in the middle. You can get very imaginative with this and get an exact match with your speakers. Lots of ways to go.

All the best,
Nonoise

there are a number of usa stand makers that can do this for you, albeit at a cost

just search on ebay (where they advertise basic models) ... at least three will pop up, one in az, one in colorado, one in tx

all with decent reputations

Local cabinet maker is the best route.  Etsy also has offerings.