Here, we will look at Patent Term Adjustment (PTA), specifically when PTA applies and how a longer term can be obtained.

India-UK FTA excludes patent term extensions and data exclusivity, safeguarding Indian generic drug industry interests.

You can find The Manual of Patent Examining Procedure online—they have PDFs dating back to 1948. So I pulled the one from July 1958, the latest copy you can get that Harry might have had.