This is what shows up for me (California):
Thanks Bjorn. Yeah, that is pretty much the same google results I get up here. Almost all the images show the proper Fiat flat gasket. Much like the one I have here. But do note, most show a gasket of slightly different construction to mine. So yes, most likely Bosal changed the design at some point, or more likely just bought in the gasket from a different supplier as time went on.
I can assure that my gasket was a Bosal product, and was in a sealed Bosal package before I opened it to take a pic and measure it.
On that page of google images, almost all show that gasket. On those images that show a donut gasket, when you click into the image, it leads you to a different gasket, like 256-992 which is a different Lada gasket.
Perhaps somewhere on the internet, you may find someone who posted an incorrect image of a Bosal 256-749. Mistakes do happen.
But I can assure you, there are certainly not two different gaskets with the same Bosal part #. If you order a Bosal 256-749, and indeed get a Bosal 256-749 in a sealed package,it WILL be the proper Fiat flat gasket. But....I cant guarantee it will have 38mm ports like mine.
I still reckon your best shot is to find an older stock product. And your best shot of that would be in North America where that gasket - unlike europe - was only used many many years ago.
I can certainly understand why most North American sellers dont bother with the hassle of taking a pic of a $2 part. I guess you could contact them and ask for a pic and port measurements, but good luck with that......
Other than that....you pays your money and takes your chances.....Both the listings I linked to are still active, so I guess nobody here has cajones that large. Just for curiosity's sake, I tried to order them, but neither vendor would ship to me in Canada.