| # | Entity | Status | State |
|---|---|---|---|
| 1 | 11 841 060 383 E.J DUFF & G.W DUFF |
ABN Active | NSW 2283 |
| 2 | 12 709 842 440 D.A DUFF & G DUFF & H PALMER & D.W PALMER |
ABN Active | SA 5213 |
| 3 | 92 966 959 425 P.G DUFF & W.L DUFF & P.R ENGLAND |
ABN Active | QLD 4558 |
| 4 | 13 741 082 254 G.W DILLON & J.M DUFF |
ABN Active | NSW 2440 |
| 5 | 82 531 960 506 W & G DUFF |
ABN Active | TAS 7306 |
| 6 | 90 304 844 889 G.W. & A. DUFF |
ABN Cancelled | TAS 7306 |
| 7 | 95 572 638 796 M.A DUFF & G.P LYNCH & W.R LYNCH |
ABN Active | NSW 2794 |