Rubik's Tangle 3x3 Double Sided

Produced in 1995.
(nine 2" square plastic pieces, patterns on both sides)

Arrange 9 squares in a 3x3 array so that edges match. Each square has on both sides the same pattern of 4 tangled ropes that has two connections on each edge. Different sides of different squares have a different combination of the four colors (red, green, blue, and yellow). More confusing than Rubik's Tangle 3x3 because one has to decide how to flip the pieces.

Further reading:
Jaap's Page, from:
McFarren's Page, from:
Thurston Patent, from: - patent no. 487,798