On the isomorphisms of the maximum subalgebras of the R. Robinson algebra

It is proved that the maximum subalgebras of the R. Robinson algebra (if they differ from $\mathfrak{A}_{\{0\}}$) can not be isomorphic to the arbitrary subalgebra of the same algebra and the subalgebra $\mathfrak{A}_{\{0\}}$ is isomorphic to the countable set of its own subalgebras of the special type.