After many comparisons done to convince myself, I believe now that your analysis is correct and that we share a coin from the same reverse die.
Many thanks Peckris 2 for responding and taking the time to share your thoughtful and thorough analysis. From South Florida USA to SW England...it is much appreciated!
Link may be of interest https://weeds.brisbane.qld.gov.au/weeds I think Hedychium Gardnerianum is listed somewhere in it. Nevertheless it is still grown in Brisbane gardens as it is an attractive plant but can be invasive if not controlled.