Bagpipes bearing silver offer up some great clues as to profiles and details from year to year. Small differences crept into the manufacturing, either by design or otherwise.
Above - Silver by Frederick Narborough 1956. To the right and immediately below, one of the more unusual sets I've found. The silver bears stamps of RGH and of Dalman and Narborough with date letters stretching from 1953 to 1957. I've chosen to interpret the set as having been made in 1957 although closer examination might lead me elsewhere.
The set above - Silver by Frederick Narborough 1961.
This set - Frederick Narborough 1963.
By 1971 the quality of Hardie bagpipes was slipping badly. Short cuts were taken to hasten delivery and lower costs. Many bagpipes were sent out without proper reed-seats or other critical finishing.

Present ownership has restored quality and respect to the Hardie bagpipe name.
R.G. Hardie