The CAHA had become the largest amateur sport body in Canada by 1928, and control of the Allan Cup was transferred from its trustees to the association.

[4] Sandercock excelled at sprinting and track and field sports as a youth, and later served as an executive with the Ontario Hockey Association.

The AAHA instead concentrated its energy into junior ice hockey and winning the Abbott Cup as champions of Western Canada.

[11] In November 1925, the AAHA passed a by-law to issue its own registration cards if it felt a player was declined by a spiteful administrator of the Alberta branch of the Amateur Athletic Union of Canada (AAU of C).

Sandercock sought for the AAHA to require its members to get AAU of C registration cards to remain eligible for national amateur competitions.

[14] In February 1925, Sandercock submitted a proposal to change the Allan Cup finals to a best-of-three games format instead of a two-game series decided on total goals scored.

[29] In March 1927, the AAU of C recognized "that the CAHA was the largest and most influential amateur sport body in the Dominion" [of Canada].

[32] The CAHA updated its constitution by request of the AAU of C, which automatically suspended any players with ties to professionalism until the case was investigated.

[34] Sandercock sought for the autonomy of each sport within the AAU of C to govern its own affairs, and noted that the idea had reoccurred in Western Canada for several years.

[37] Sandercock scheduled the 1928 Allan Cup final to be hosted in Ottawa, to coincide with the location of the upcoming annual general meeting.

[38] On March 26, 1928, control of the Allan Cup along with a surplus of $20,700, was formally transferred to the CAHA by William Northey in a ceremony at the Château Laurier.

[2][39] During the annual the meeting, the Maritime Amateur Hockey Association was added as a new branch of the CAHA, and W. A. Fry succeeded Sandercock as president.

[40] In October 1936, Sandercock acquired the dental practice of the recently deceased Dr. R. J. Johnston, and relocated to Drumheller, Alberta.

[42] Sandercock became involved with the Rotary Club of Drumheller and led multiple efforts as chairman of its community service committee.

In November 1938, he aimed to raise funds to build a wading pool for the town, supply new gravel for the school grounds, and provide an oxygen machine for the hospital.

[44] Sandercock oversaw the theatrical production of Ten Nights in a Bar-Room and What I Saw There in 1939, and was appointed to the committee to recognize accomplishments of local professional hockey player Tommy Anderson.

[45] In August 1939, Sandercock gave a speech at a Rotary luncheon about the history of the petroleum industry in Canada and the world.

He spoke about the global impact of the petroleum industry on warfare, and sought for sanctions against supply to Germany and Italy in advance of World War II.

He pursued an interest in fossils as a hobby, and amassed a large collection from the badlands in the Red Deer River valley.

[47] The Calgary hockey organization which Sandercock founded had grown to include 232 teams within 15 years, and its graduates were playing in all of the professional leagues in Canada and the United States by 1928.

[53] After moving to Drumheller, he donated the Sandercock Trophy awarded to the champion of the Red Deer Valley Junior Hockey League.