Over here we also had larger butt-sets which were more a portable case with a shoulder strap in order to contain everything. They carried dry cells internally so that they could work as a local-battery phone, and even a transistorized ring-voltage generator so that they could be used to call and talk to a subs line which was isolated from the C.O.
The LB feature is pretty much a thing of the past now, but of course those old units didn't have DTMF, CLID, and would certainly not be "DSL safe."
