Are original Dolch keycaps off of a Dolch PAC computer keyboard doubleshot?
Not all. Dolch PAC-60, 61, 62, 63, 64 and
some PAC-65 have a Cherry keyboard with Cherry doubleshot key caps.
Some PAC 65 have a scissor switch keyboard instead. There are earlier models with Cherry MX blue switches, different layout and pad-printed keys (in the same colour scheme) and there are newer models where all keyboards have scissor switches.
The Cherry switches in the good keyboards are vintage Cherry MX Blue, which some find superior to modern blues. So don't throw them away!
You can put the dolch pcb into a cherry case and solder on ps/2 cable.
You should not have to
solder on a PS/2 cable. There is always a connector, either mini-din on the outside or 4P4C on the
inside and the protocol is always PS/2. That means that you need only make a new cable.
Personally I like the Dolch case more, because it is flatter and less creaky, but not everyone likes the styling of the case...
You can read more about the Dolch on the
Deskthority Wiki.