It is a Kalanchoe and I believe it is tomentosa. Got this from Guide-to-houseplants: Kalanchoe tomentosa [1] or panda plant, also known as pussy ears and chocolate soldier, is a succulent plant in the genus Kalanchoe. A native of Madagascar, it is a fairly popular houseplant on account of its small size, ease of care, and dark-red rimmed foliage Panda Plant Care Tips Origin: Madagascar Height: Up to 1 ft (30 cm) indoors Light: Bright light to full sun. Put this succulent in a bright location year-round. If you move it outdoors for the warm months, move it gradually into full sun to avoid scorching its leaves. Water: Water thoroughly, allowing the top 1 in (2.5 cm) to dry out between waterings. Humidity: Average room humidity Temperature: Average room temperatures 60-75°F/16-24°C Soil: Cactus potting mix. Fertilizer: Feed monthly in spring and summer with a balanced liquid fertilizer diluted by half. Propagation: Take leaf cuttings in spring or early summer. Succulent cuttings root easily in moist sandy mix or perlite.

Nice plant. If E. craigiana, they have brownish or brownish-green leaves. They have red flowers, so if it blooms it will help with ID. Otherwise, as you know, many succulents will change the color in more light.

If the pot is glazed inside and outside, it doesn't breathe. Good that there is drainage hole. You can use it, but I would suggest using very well draining potting mix, and water only when mix is almost dry all the way. I use many plastic pots that don't really breathe, but there are many drainage holes in each, and the mix I use is made of grit, perlite and some turface.

Thank you so much for your replies! You're right kara, they do look like they're light-starved but strangely they've always been in full light on a window ledge (I moved them to a wall to take the photos!). I first bought the original plant (in the orange pot) from a garden centre - it was helpfully just labelled 'succulent', and was much smaller. Also it's worth noting the leaves weren't very curly at all when I first bought it! They were classic straight leaf shape like the propagated cuttings, and the stem was much less woody and coarse (and green) - it basically looked like the fresher propagated cuttings in the 2nd photo. I think the poor original plant might be a bit pot-bound now.. elucas101, those do look quite a lot like them but I can see mine aren't quite growing in the same way and sadly these guys don't seem to get flowers! (or at least they never have with me..) It's a really lovely plant though! Hm, these guys are a bit of a mystery!!