Repairing calibrators is always fun. This one had no output. It has the 120mA option but that was dead too. The fuse was blown, a logic-opto and a p-channel jfet were dead. The IC caps had a very high leakage current. The jfet was obsolete but I found a usable substitute. The only problem was the sot23 package. That was easy solved because it fitted on the through hole pads.
The reference is a LM299 made by LTC. The 120mA option is located after the pushbutton section.