Hi,
Bolt is certainly a verrrry rare surname in Perthshire.
There is no sign of the name anywhere in the Directory, that I can see.
I can scan the Perth (town) pages if you are interested.
However, I do have a record of a mariage in 1904.
Jessie Crerar to Fredrick Bolt.
Fredrick's parents are given as William and Betsy Ferguson.
Jsssie's are John and Margaret McArthur.
On the 1881 census:
Dwelling: Dargill Cottage
Census Place: Muthill, Perth, Scotland

Marr Age Sex Birthplace
John CRERAR M 42 M Dunning, Perth, Scotland
Rel: Head
Occ: Ploughman
Margaret MC ARTHUR M 40 F Killin, Perth, Scotland
Rel: Wife
John CRERAR 14 M Auchterarder, Perth, Scotland
Rel: Son
Occ: Tailor
Peter CRERAR 11 M Crieff, Perth, Scotland
Rel: Son
Occ: Scholar
Jessie CRERAR 1 F Crieff, Perth, Scotland
Rel: Daur


I cannot help with the Bolt or Ferguson Family, but have plenty on the Crerar and McArthur Kin.
Awrabest
Davie