I had exactly the same problem and I bought a pair from Franzose and they fit a treat (as expected) but they are basically just Valeo V28 (280mm or 11" long) and although I'd ordered a load of stuff so didn't mind the few quid extra, if they were all I needed, I'd try more locally first. They are also the type listed for later Classic Minis and widely available from various online suppliers (including a few on Ebay) and probably from your local motor factors; in fact I would also take a look at other brands which are listed for the later ('90s onwards) Classic Mini with the black wipers (earlier Minis had 10" blades).
Funnily (or probably not) the plastic "ends" I had on my arms were identical to the ones in your photos and I simply could shift them by manual means (you get nice new ones, not identical but new ones, with the wipers) and they were too narrow anyway so in the end I very carefully snipped them off with a pair of wrire cutters and within a few minutes I had them fitted. I haven't actually tried them yet but at least they are now not torn, hard and wobbly like the last ones. Good luck. Mark B.
Hi. As my car has stainless Marchel SEV wiper arms, I wanted to keep that retro look, so I got a pair of 10inch Tex stainless blades from Holden Classic and Vintage parts. Not cheap, but they do the job well, and look the part.