You’d think by now SOMEBODY would be producing something, especially with the Third and Fourth Doctors be associated with UNIT soldiers! And it would really go with the Alvis Saladin on my bench…
A 1/35th Dalek would also be useful !
Or a Cyberman or Movellan or Sontaran…
i thibk your best bet is to find someone selling 3D STL Printing files and get them to re-scale them to the size you want.