Hi,
I am building an old pre PSShips Sirmar TID Tug that I purchased many years ago and put aside until I had a workshop, from what I can tell after looking at photos of other models and different plans there is no standard for the TID tug. Some have glazed portholes on the engine casing vents whilst others are just blank hinged steel plates. Also my plans state that there is a porthole only on the port side of the accomodation(?) access in front of the wheel house yet the photo of 164 clearly shows a porthole on the starboard side. The raised skylight shown in the photo in Kemo's post is shown as a flush porthole on my plans.
My best guess is that whilst the hull and superstructure is built to a standard plan they were fitted out to each owners specification, unless of course they were modified in later life? I personally will build it according to Adrian Brewers drawings and the fittings that were supplied. I look forward to seeing a glut of TIDs at the various shows.
Clive :)