I have a pack of the stuff, passed to me by a friend. The brand name is;
ETHICON, size 5-0 & there is a code on the tube label; DS - 35.
My friend probably got it from Hannants in the UK, they are on the web, but beware their shipping prices!
I just used it to rig a 1/45th scale swordfish & have used it to rig WW1 planes for my friend. It's fairly easy to work with, but takes some planning as once bent, it's hard to straighten. I found the easiest way to work with it is drill through the lower half of the topwing. Then drill right through the lower wing. Cut to length, about 1 inch too long. Superglue into top wing, making 1/4 inch bend on end first, this gives a bit of an anchor in there. leave overnight, next day, put a drop of superglue on the free end and feed it quickly though the lower wing, then clip a Boston (USA) / Bulldog (UK) clip to it and let it hang, gravity will tension the wire and hopefully the top bit won't pull out! Cut to length next day as close to the wing underside as possible using a sharp scalpel.
This method works but is guaranteed to send you blind or insane!, especially on something with lots of rigging, such as the 1/72 Gotha I built!
But when it's done, and you can sit back, the result is far better than stretched sprue and more to scale than phone wire, especially in 1/72.
Her's a thought, what about ordinary power cable wire (multistrand), it will be more flexible than surgical wire (& Cheaper) and so long as it's silver in colour, the above method should work, and look good.
Happy Rigging!