Having started on the Bolt Action Home Guard Mark IV (male) World War One Tank. The first stage was to clean the resin and metal pieces and then wash the resin pieces in warm soapy water to remove any residue from the casting process.
The parts were quite easy to clean and they fit together quite nicely and easily. Here are the resin pieces.
They comprise the hull, the two track units and two sponsons.
Here are the metal castings.
As well as the fascine rails, you also have metal main weapons and secondary weapons, exhausts and other hull fittings.