Would it be possible for Trainer to provide a brief Tutorial?

Modelling Ports from existing "building blocks" is something I would be very happy doing, if Trainer could let us know a few secrets.
I can see the file structure by looking at the .dat file (eg St_Nazaire.dat) with skwas "Silent 3ditor", but not too sure how the dat files really hang together. Have tried renaming a dat file, and playing about by reducing the number of placements, and changing a few parameters, but then flashing up SHIII to see what things look like each time a change is made is very tedious. If this is what Trainer does, then my hat is off to his patience!!!
For example all the different placements. I think the offsets are from the port location in Locations.cfg. Not sure what the rotation is measured in (not degrees I don't think). And where do the names like "Fabrik_Halle_01", "88mmGEDoubleT_L_Load_05" get picked up from etc etc. I have tried doing a Text search across the files but cannot find them.
MLF