Help To ID Joseph Moreau Merchant Countermarks On Silver Coins

Hi all!

I am posting this pair of well circulated Halfcrown-size silvers. I bought them when I was living in Montreal around 10-15 years ago. At the time, I just liked that they were two punches from the same countermarker, and that they gave a little glimpse into the mix of circulating silver specie in the mid-19th century (judging by wear, look of the punches, the introduction of provincial / federal issues, etc.) in Canada / possibly the N-E USA.

They appear to be two punches from the same merchant / craftsman, one on an 1817 British Halfcrown reading "JOS MOREAU," and the other on a Bolivian (Potosi mint) 1778 4 Reales reading "JOSEPH MOREAU / JM / JM."

I have tried researching them quite a few times over the years, and turn up little or nothing (I unfortunately don't own a Brunk, but I have looked in my Gavin Scott cat of British c/ms, and he doesn't appear there). I'd like to know if anyone can find reference to this person, or these countermarks - any leads or info would be hugely appreciated.