Needles.According to ISMACS, the 12x1 was made by Schmetz under the designation 257 or 339 or 23:51 and by Groz-Beckert (no number given) but my local supplier has no listing whatever for this needle, meaning... (insert dramatic music here) they don't make them any longer. Well, this is no big surprise. According to the lady responsible for http://sewingtales.wordpress.com/2014/07/06/needles-and-my-singer-12/ if you can get one in there, a common 16x231 will work. Well, I tried and the needle clamp wouldn't play along (sigh).
My new best friend Steve in the U.S. is sending me a couple of his, and I'm ordering some old stock from a place in Switzerland just as soon as they let me know how to pay for them. If they come through I'll tell you who they are, but I won't recommend them if they're not reliable.
There's a lady on Etsy who sells them, but she won't ship outside the U.S. (boo!), Alex Askaroff has a few left apparently and you could get some massively overpriced ones from eBay. I find the latter to be full of people charging too much for everything. It seems to coincide with eBay's constant fee changes, like the fact that they charge you the selling fee plus postage. This means that if you sell something heavy (e.g. a machine head) to an overseas person for the 99c recommended starting bid and it costs $300 to send it to them, you not only lose the money you paid for the item, you're left with a $30 fee plus paypal charges! It used to be a great way to sell things but greed always seems to spoil these things.