I spent hours at the salvage yard going through old clip-ons to look for ones that would fit and meet my aesthetic ideals. I came up with the 2006 Suzuki SV650. The clamps vary from 41.5mm to 40mm when fully screwed down. This should work perfectly on my 41mm shock tubes. One of the handlebars is totally intact, the other is a bit screwed up. I can deal with the damaged section.
Here's a shot of the new clip-ons. You can see where I've been filing off the protrusion that slotted into a hole in the underside of the SV650 steering stem head.