These fantastic tweeters are a 4 Ohm, 91/dB/w/m design with a ruler flat frequency response from 6kHz to well over 20kHz. The winner of the auction got a bargain as they were over £100 each when you could still get them!
The ones I searched after turned out to be the Multicel which came in many guises. Indeed almost rulerflat from about 5k to beyond 20k. Decent sounding. Here (NL) still available in surplus for 20,- euro each.
The tweeters that 'ronning' posted an image of, and I posted the eBay auction to, are different to the ones you asked about all those months ago.
Johan's link is to some tweeters with four mounting holes and four other holes 'either side' of the ribbon.
'ronning's question was about a picture of tweeters with four mounting holes and four other holes 'above and below' the ribbon.
I was watching the same eBay auction as 'ronning' was, and compared the images in that auction (one of which 'ronning' posted) and the size of the tweeter also described in that auction. Please believe me when I say that the ribbon tweeter in the picture copied by 'ronning', and the dimensions of it as quoted by the eBay seller, is completely identical to the Japanese built Tonigen Ribbon that I have three of.
Absolutely, indefutably, identical - not just similar - and certainly not available at any old surplus store!
Other ribbon tweeters may be as good and as sensitive and as 'flat' as the Tonigen but you will never buy them as cheaply as the JVC or 'others' mentioned in this thread!
Basically, I wish that I had a lot more money and could have outbid the winner of the eBay auction that prompted this thread!