......How many courses did he DO in the UK after 1926?
My guess would be that his brother still oversaw the work, or just did the work himself. But Alister was still making regular trips back to the UK through 1932, according to the MacKenzie Timeline project, so it's possible he oversaw some work there.
I've had a quick look-see at the Timeline.
It seems that from 1926 onwards he was still involved with various ongoing/already underway work including with his brother, 'Major' Charles.
As to 'new' GB&I projects that came along from 1925/6 onwards these were apparently -
Worcester
The Worcestershire (Malvern)
Pulrose/Douglas (Isle of Man)
Lahinch
Limerick
Otterburn Hall (Northumberland)
Walsall
There are references in the Timeline to his brother Major Charles being involved at The Worcestershire and at
Pulrose/Douglas.
There seem to be no references in the Timeline to his brother in relation to Lahinch, Limerick or Otterburn Hall.
As to Walsall, this would seem to be a considerable revamping of his course from several years earlier - due to a new road bi-pass system. There is no mention in the Timeline of his brothers involvement in the later Walsall work though, but if his brother was involved in the earlier work......?
Other than previously ongoing/underway projects Would this be the extent of all his GB&I work from 1925/6?
Given the close geographical proximity there would seem the possibility that the work at The Worcestershire (Malvern) and at Worcester could have been conducted by the same constructor/onsite rep and even construction crew, ie maybe Major Charles, particularly as The Worcestershire opened one year before Worcester. Walsall isn't that far away either, but the work there wasn't finished for a few more years so maybe not so likely.
Lots of conjecture, speculation and 2+2=5 kind of stuff though.
Any information or advice from the MacKenzie community would be welcome.
Atb