The realization space is
  [1   1   0     -2*x2 + 1   0   1   1          0      -2*x2 + 1             x1    1]
  [0   1   1   -x1*x2 + x1   0   0   1         x1    -x1*x2 + x1    -x1*x2 + x1   x1]
  [0   0   0             0   1   1   1   2*x2 - 1   -2*x2^2 + x2   -2*x2^2 + x2   x2]
in the multivariate polynomial ring in 2 variables over ZZ
avoiding the zero loci of the polynomials
RingElem[x2, x1*x2 - x1 - 2*x2 + 1, x1 + 2*x2 - 1, x1 + x2 - 1, x1 + x2^2 + x2 - 1, x1^2 + x1*x2^2 - x1 - 2*x2^2 + x2, x2 - 1, 2*x2 - 1, x1*x2 - 2*x2 + 1, x1 - x2, x1 - 1, x1, x1*x2 - x1 - 2*x2^2 + x2, x1 + 2*x2^2 - x2, x1^2*x2 - x1^2 + 2*x1*x2^3 - x1*x2^2 - 2*x1*x2 + x1 - 4*x2^3 + 4*x2^2 - x2, x1 + 2*x2^2 + x2 - 1, x1 - 2*x2 + 1]