Mervyn
I used to have a photo permit for Leith Docks, and on my visits 2 or 3 times a year between 1983 and 1993 would usually see the tugs in the Victoria Dock within Leith Docks - the Forth Tugs vessels were supplemented by Irish firefighting tug BRANDON BAY in February 1985 while BOQUHAN was refitting at Grangemouth.
When tankers were being brought alongside at Hound Point all four tugs were used, with the firefighting ones tied alongside with their masts poking above deck level. I have photos of this, but not up to Shipspotting standards...
If there was a tanker at Hound Point, one of the tugs would be based at the buoys there on standby. I saw both firefighting and non-firefighting tugs in this role.
The tugs were drydocked in Grangemouth or Leith.
By 2016, when I started paying attention to ships again, the Hound Point tugs of Targe Towing were always moored to buoys between Hound Point and the railway bridge.
Mike