I see the answers that have come in to the online site. My thanks to those who responded. I may be wrong but one or two of the writers seem to think that I make a connection between the coins and Leichhardt. Nothing could be further from the truth. The answers confirmed what I already had discovered - the original identification of the coin was a mistake that writers about Leichhardt ever since have taken as accurate and continued to cite in speculation about a possible Leichhardt connection. The only question that remains unanswered is the number of Maundy threepences minted.
I believe there is no connection between Leichhardt or any other white men and the site where the coins were found. The site is an Aboriginal site, pure and simple. In the early days every second Aboriginal campsite had items of European manufacture on them. European goods were at least curiosities and at best valued and sought after for use, particularly iron axes and knives. European items moved great distances along traditional trade routes which undoubtedly is the origin of most of the European goods found in remote Aboriginal campsites.
I have another record of coins being found on an Aboriginal site. In 1934 five shilling pieces were found in a lakeside camp on the east side of the Darling River. Three of them were dated 1826, one 1834 and the other 1845. Typically, the finder (not I) wondered if they might have some connection with Leichhardt!
Once again, thank you to those who responded and thank you, too, Wayne, for including my query in your journal.
Thanks to all who responded on this topic.