There are similarities, yes, but the trailing edge of the model seems to be straight, giving the
wing a DC-3 like planform. The tailplane loks extremely rhombic on the other hand.
About that model I saw,: Yes, AFAIK some components of the Stirling were indeed "loaned2 from
the Sunderland, or t leat very similar, but here just the planing bottom was cut off and replaced
by a rounded and shallower underside. Just artistic freedom and that's what's often can be found
on such models.