Fascinating story, and some of the details sound very curious.
Selkirk may be a "small town" by southern standards, but it serves a large rural area. Historically it is a county town, the administrative capital of Selkirkshire, with its own Sheriff Court.
Until 1946 Selkirkshire had its own police force, now part of Lothians and Border Police, who still have a manned police station in Scotts Place Selkirk.
On that basis, it seems quite surprising for someone who ran a business in the town to say that "As for the police, Selkirk was then and largely still is a one horse town.There may have been a Bobby on a bicycle."