Sean
Us amateur researchers undertaking the timeline project for the AM Society - Sean Tully, Nick Leefe, myself, Mark Bourgeois (and previously Bob Beck) are also looking into his courses as a natural extension of finding out information for the timeline. Sean T started a spreadsheet on a list of his courses and what I have done is further extended this by adding all the listings from DSH, C&W and Hawtree (Colt&Co) which are the the three main lists of Mackenzie's work. Some courses are on one list and not on another and vice versa. And then I have added all the courses I could find from Mackenzie's 1923 and 1929 adverts, many of which were not in the three lists.
I have then put these into a few different categories - confirmed, question marks (where we have some info but have not been able to fully check it out yet), misattributed, courses where he gave advice or did a design that was not implemented (eg El Boqueron), and another category for wildly improbable but a mention somewhere. As we go along and learn more, there will be shake ups in these provisional categories and some will go up into confirmed and others will go into misattributed etc etc.
But this is more than just a list as in a comments column we are endeavouring to summarise just what AM did on each of these projects, whether it was advice that wasn't taken up, whether he advised them on a new course pre-WW1 which stopped everything and the restarted again after the war - and there are many of these, or whether the whole course design can be attributed to him. Every one case is different as you would appreciate and I don't think its worth talking in generalities.
Many many of these clubs have proof and some just don't know it. I'll give you an example - Crowborough Beacon. I recently came across an old Darwin handbook for the club and in it was a mention of the 7th hole being out of commission as it was being reconstructed by Dr Mackenzie. No mention of AM on the club's website or history book, but Darwin was rarely ever (if ever) wrong about matters of architectural attribution so I contacted the club and explained this to them and they went back into their records and sure enough they found documentary evidence in minutes and annual reports confirming Mackenzie's involvement. It seems it got glossed over as there was one member of the committee around the time who was Dr such and such and another who was named Mackenzie and so the references were missed! So there's a serendipitous find that was on no-one's list.
Certainly old attributions are hard to kill as you say but detailed digging in partnership with these clubs seems the only way to go to sieve the myth from reality.
Bill
That's what I thought about Newcastle too, perhaps he included it because of the Colt connection, but apart from Portrush and this one, the others pretty much all seem genuine Mackenzies. However, based on the advert its worth a follow up with the club I would say on the off chance that he did give them some advice.
Neil