In following through my research into the list of courses Mackenzie claimed he had consulted to that he included in his 1923 brochure, Royal Eastbourne was one of those courses that had not previously been associated with Mackenzie and was missing from the Doak Scott Haddock, Hawtree and Cornish& Whitten lists. My enquiry with the club elicited a detailed reply from their historian, confirming Mackenzie's involvement in the period 1920 to 1925, with an involvement in the construction of the 17th green in 1925 by his brother Charles (albeit not entirely satisfactory).
Here are the relevant entries from the Club's Council minutes:
Extract of the Minutes of the Club Council October 23rd 1920 - Suggestion Book
A widely supported suggestion about the improvement of the existing bunkers on the course having been put in the book, the Council instructed the Secretary to writ e to Dr. A. Mackensie and to enquire what his charges would be for a report on the bunkering of the Course and whether he would be free to come here at an early date.
Extract of the Minutes of the Club Council 26th November 1920 - Course Improvements.
A letter was read from Dr.A. Mackenzie in answer to one from the Secretary asking of he could pay a visit to this course and advise as to the improvement of the bunkering. Mr Steele proposed & Col.Stainsforth seconded that Dr.Mackenzie be asked to come as soon as possible. Carried with one discentment.
Extract from Minutes of the Club Council December 29th 1920 - Dr. A. Mackenzie's Report.
Dr. Mackenzie's Report which had been printed and posted to every member, was considered by Council who agreed that for the present it was inadvisable to proceed to the construction of new holes. Rev.F.S. Williams proposed & Gen. Roper seconded and the Council agreed that the Report be referred to the Green Committee for consideration and that the latter should report to Council at an early date.
Extract from Minutes of the Club Council January 19th 1921 - Green Committee.
A report from the Green Committee was read giving in detail the improvements they suggest should be made in the Course, and recommending that Dr. Mackenzie be again approached to find out if he would be willing to carry out these suggestions and what the approximate cost would be. Mr. Harding proposed that the Green Committee Report and suggestions be adopted. Mr. Steele seconded and the Council agreed.
Extract from Minutes of the Club Council February 8th.1921 - Course Improvements.
Dr. Mackenzie having gone over details with his contractor and foreman the work which the Green Committee had set out as necessary in the Report, now estimated that for an expenditure or £800 (eight hundred pounds) practically all the suggestions could be carried out quite efficiently. Gen. Roper proposed that the sum of not more than £800 be expended in carrying out the work, this sum to include all architects and contractors commissions and charges. Col. Crompton moved as an amendment that Dr. Mackenzie be informed that the Council were willing to spend £800 on the necessary work and that future commissions should be additional to this sum. Mr Harding seconded the amendment which was carried.
Extract from the Minutes of the Club Council May 13th 1921 - Course Improvements.
The Hon.Treasurer spoke on the financial side of the work which had been carried out on the course. The Contractors charges amounted to £485.0.5p. Sand for the new bunkers £73, and in addition there were the Architects, Dr. Mackenzie's fees.
Extract from the Minutes of the Club Council July 25th 1921 - Dr. Mackenzie's Charges.
Dr. Mackenzie's a/c for his professional services included a commission on the whole sum which he was informed the Club was prepared to spend on the reconstruction of the course. The Secretary was instructed to write to him to say that the Council considered they ought only to pay on the amount actually expended to date and that the remainder would be paid when the work was carried out.
Extract from the Minutes of the Club Council October 17th. 1921 - Course Improvements.
the Council decided to leave this to the Green Committee as before, the task of drawing up a schedule of further improvements to the Course to be carried out by Dr. Mackenzie this winter.
Extract from the Minutes of the Club Council December 23rd 1921 - Work on the Course.
The Secretary reported that work on the Course would stop that day and as roughly about £315 had been spent since the resumption of the work, only about £50 remained of the £1000 originally earmarked for the improvements. Mr. Peacock proposed that the work stop from this date. Col.Harrington seconded and the Council agreed.
Extract from the Minutes of the Club Council October 24th 1924 - New 17th Green.
The Green Committee reported to the Council the result of their interview with Dr. Mackenzie with regard to the construction of a new 17th. green and the Council decided to carry out his proposal and hoped every endeavour would be made to put the work in hand at the earliest moment.
Extract from the Minutes of the Club Council February 17th 1925 - New 17th Green.
The Secretary reported the amount of work he had carried out on the 17th. green to rectify the bad work done by Major Mackenzie's men. It was agreed that the Secretary should interview Major Mackenzie and try to get some reduction in his account by way of compensation.
Extract from the Minutes of the Club Council March 26th 1925 - New 17th Green.
The Secretary reported the result of an interview with Major Mackenzie with regard to the unsatisfactory condition in which part of the 17th green had been left. Major Mackenzie agreed to a reduction of £10 in the amount of his charges.