You can make your own G-claron or Symmar casket set from modern or fairly modern lens cells. The real problem is that nobody makes long focal length cells that fit into the same shutter as the shorter lengths. Most of the cheaply available plasmat series jump into a Copal 3 shutter at 240 (plasmats) or 360 (dialytes) so it is hard to assemble a set with a decent range of focal lengths.
But, with a Copal 1 and the cells from a 150 and a 210 Symmar you can get a lot done. 150 and 240/270 mm G-claron cells give you a bit more range (but with larger gaps).