Machins Mills series was a series originally developed by Bob Vlack and others in his generation in terms of its creation and build-up. Its original listing of varieties was done by punch linking, categorizing certain traits like unfimbriated cross-bars (i.e., solid crossbars) and most importantly die linking to U.S. Colonial State Coppers which IMO is the only feasible method as I wrote in my Broken A Letter Punch paper for the ANS sometime in the 1990's.
With time the idea of categorizing varieties with punch linking due to the hub matrix principle became unfounded (i.e., which is why a lot of the Breen U.S. Colonial attributions are nonsense) and a lot of the earlier varieties away from the central core period (i.e., specifically 1787/1788 issues) became speculative in my opinion as to whether they we ever produced in Machins Mills. You need to understand something of Machins Mills pieces - there is NO EVIDENCE directly that these were EVER produced in Newburgh, NY. Just like the GNL Class 1 CC8R at
The Royal Mint, the Canadian Blacksmiths in Lower Canada, etc ... we work on probabilities based on experience and any indirect evidence which comes forth to us in our studies. Since the 1787/1788 types are die linked to U.S. Colonial State Coppers (i.e., like Vermonts and Connecticut's) these have a higher probability of being produced in Newburgh, NY. Certain non-1787/1788 issues due to prices,
Red Book inclusion based on tradition, etc. simply are considered Machins Mills pieces just because several notable numismatist's three decades ago said they were - one of the problems with contemporary circulating counterfeits (CCC) is the lack of written evidence and with that - assumptions, gut feelings, experience and probabilities of origin then enter the equation.
So to answer your questions what of this 1772 issue? This is simply a seller taking a legitimate English CCC and since its similar IN APPEARANCE to one of these so-called Machins Mills pieces is also calling this piece American Made rather than what it really is a British import CCC. A $10 coin. IMO - no harm - no foul.
Some seasoned Colonial Collectors will continue to honor these Vlack listings for all these dates and varieties and some people's pocketbooks are forced to comply - be that as it may.
Unfortunately - Material Analysis can not yet differentiate between American made colonial coppers and British imports for copper in the 18thC. Lead Isotopic Analysis has shown some promise but we are easily around 50 years away from this type of differentiation.
Do I believe the 1787/1788's are American - YES with a high probability factor. Other dated Vlack varieties - NO (low probability). IMO.
See my new book coming out in late 2016 on various CCCs with much information on Material Analysis. Year by year Ed - we are getting better however - politics, money, traditional values, etc. always tend to TWIST advancements in this field of CCC's - the usual ...
JPL