Brass Birmingham insert risers with symbols

These risers can be put into the insert slots to raise all the industry tiles to the same level without having to print a completely new insert.

UPDATE: One of the walls was too thin, it is fixed now in the new version. Also the coal cart symbol is corrected a little.

Differences of the remix compared to the original:

These risers are a bit thinner (0,2 mm) than the original, to fit better to this insert: (not the one in the original): https://www.printables.com/model/68057-brass-birmingham-board-game-inserts

Two of the risers is made taller too, to compensate the different heights.

And they have symbols on them, to know which building should go in which box.