I just checked my list and I have recorded stampings on 1x$2 (number); 13x$1 (11xnumbers & 3xletters); 2x50c (1xnumber & 1xletter), and 5x20c, (3xnumbers & 2xletters). No 10c stampings that I've seen reported yet, so it's a first.
Not all the ones I have listed are mine, just what's been mentioned on the forum/s. I have 7 as below (out of 21 recorded up to May 2007), but I do have others not on the list yet.
Denom Year Position /Side
20¢ 1967 0 - left of date /Rev
20¢ 1968 U - left of date /Obv
50¢ 1975 E - left of date /Obv
$1 1997 Smithy 0 - between date & neck- both sides /Obv
$1 1997 Smithy 0 -- on wing + fuselage -- "/Rev -- as above
$2 1998 3 Upside down - on neck /Obv
20¢ 2004 large 5 over 4 /obv
life is a mystery to be lived not a problem to be solved