Here's a belt that would interest historians, mechanics and musicians
No metal to scratch or damage fragile materials

Knot Belt (aka Snake Belt)

I was shown this design back in the 70's. I can't remember the craftsperson that showed it to me, but when I returned home I tried to recall what I saw and this belt is what I remembered. He told me that the design was 16th Century Spanish.
It is made from a vegetable tanned sole bend cowhide, about 12-14oz thickness. The thickness of leather is measured in ounces, where one ounce equals 1/64 inch. So in inches that's 3/16" to 7/32" (.188" - .219"). As you can see it is quite thick and that thickness lends itself to this marvelous design.
In the years following I made about a dozen of them, all custom made and sized for each customer. This one is my old belt. Not for sale. (Maybe someday it'll fit me again.)

Here's a buckle that would interest modernists and design engineers
One simple piece of metal

Simple slick one-piece design belt buckle

Modernist, utilitarian, simplistic, and functional. The design is the ultimate belt buckle and quite handsome worn. It is made from cast nickle-brass and polished to a high sheen. On the back it is inscribed - BW Goldsmith, dated '75 (1975) and numbered #101/1000.

This is one of my favorite buckles. Not for sale, I still use it.