You don't need special tools for this project,  only 2 of the parts (the piston and its housing) are made from specific materials, easily available from craft suppliers. The kit available is all brass but all
parts can be made out of common household objects.


Once you have an understanding of the principles involved, you will be able to turn paper clips, toy cars and broken cassette players into cute little engines.
Aluminium foil is useful stuff, you will make the engines displacer from it, but it also makes a great heatsink and it holds small parts in place while you solder or glue them. Push small balls of scrunched up foil around ends of tubes and on moving parts to stop solder, glue or paint from clogging them.
Things that need to be in line can be arranged on a flat surface, then press a lump of tinfoil over them. They will be imbedded in a tinfoil mould while you solder or glue them
.

You won't waste time building this project, only to find that it doesn't work. Each step of the build ends with a test so that you can be sure of success. Here you can view a video of the compression test described on p12 of the manual.