If you reload Rebel has S & B 303-25 brass or Bertram brass which is made in Seymour Vic they have 303-25. Dies wise Simplex in NSW make dies, sometimes its best to send a couple of fired cases just to make sure that your chamber dimensions are the same as the dies.
The rest as Collector as mentioned.
Now the 303 Epps that was a cartridge before its time and its wildcats.