In July 1938, Andrus was interviewed by Alfred Trego Butler, who was Windsor Herald of Arms in Ordinary at the time.

After Andrus had worked for Butler for a year, his career at the College of Arms was interrupted by the outbreak of World War II.

In that year, Butler asked Anthony Wagner, who was serving as Richmond Herald of Arms in Ordinary, to take on both his clients and his young protégé.

On 1 March 1982, Andrus retired from the position of Lancaster to take on the office of Beaumont Herald Extraordinary.

[3] At the time of his death, he was one of only a few people remaining at the College of Arms who had any experience before World War II.