The heating system consists of the following:
1)a heater “core” (small radiator),
2)a plenum to cover it,
3)an interior fan and housing, and related vacuum actuators and tubing,
4) the hot water control valve
5) the pushbutton controls with cables.
I have several “used” interior fan and housing units with cable controls, I have some pushbutton controls (buy maybe no plastic pushbuttons?) I have some hot water valves.
This is not enough to make a heater. You would do better to contact a salvage yard for a complete unit.
(I used to have cores and thier housings, but I gave it all to a man who has since had a stroke and cannot speak)