I know this thread is a year old, but other a/d/s owners might find this info beneficial. Anthony of A&M Fabrication, a.k.a. Dean Van Riper, can make stands that look very similar to the a/d/s originals, and he will ensure they are perfectly sized. I see that he has had customers who had him build them stands for their a/d/s speakers. I'm a satisfied customer with no affiliation who had him fabricate a pair for my Large Advents.
My cost in September was less than $130 to Austin for a pair that were custom cut/welded, powder-coated, and have adjustable height rear spikes. They were also filled with sand and then weld-sealed, so they are nicely damped. That's the standard package. Three months on, I can say I love 'em!
Now I want some a/d/s speakers from the '80s.
Yep, these guys are out of Fort Smith Ark I believe, I have seen a couple of their ebay ads and since I just live down the interstate in Little Rock I would love to get in touch with them and try a set of their stands. If I get my hands on those L-810's I will!