Here is some ideas > http://motorbicycling.com/showthread.php?t=21321
I'm not sure what you mean by "brass cable ends". If you're talking about the carburetor end of the throttle cable you can use brass tubing, available at most hobby shops. Use tubing with a 1/16" ID, cut to length and soldered to the cable. Some builders wrap a small length of 20 to 24 gage wire, like telephone wire arond the cable and solder it.
For the 'barrel' end your mold will work or you can use 3/16" or 1/4" brass tubing filled with solder and the cable running perpendicular to the barrel length.