Models are timeless. Good hints, even 15 years ago. I bought some hardware store cable probably 15 years ago that is stainless steel. I can't solder it either. If the OP is still flying planes, I would bet that he has a computer radio by now :-) Farther back in time when there was a Hobby Lobby in Tennessee, they sold bulk hardware that used plastic air line tubing and some flex cable that could be soldered. That was in the early 1980s IIRC. Not sure how tight of a bend it could go though.