For anyone interested in these people, the Colony of Monte Grande, near Buenos Aires, Argentina founded in 1825. I have done some work on the group, using the records of other researchers, including I.D. Stewart's work, and other Argentina-Anglo records available:
You will find here an early newspaper article of the Colony sent by William Grierson to the Times, [London]. It has never been published before anywhere that I can find, since it was first published in 1829.