A simplified, improved version of thing:5814159 - "Thirteen Tiling Puzzles".

Nine heptominos are provided. The first six, seven_12, 20, 23, 24, 31, and 32, are common to all three puzzles. The next three, seven_66, 72 and 102, are added one at a time to make three sets of seven heptominos.

Each set tiles a 7x7 tray large enough to hold the 49 cubes that make a set of seven heptominos.

All the tilings are unique. The common set surrounds each unique heptomino in the tilings. It is best if the unique pieces are colored differently.

Beveled cubes are used to illustrate the heptominos - the 108 heptominos
can be seen on wikipedia - https://en.wikipedia.org/wiki/Heptomino

For answers and more information see "How Done" below.