Hello oplink1,
the scope 1624 is similar as type 1604 except the differential inputs. Main circuits are the same and you can use the service manual found here for free:
http://www.eserviceinfo.com/download...1602/1604.html
The problems with the battery described by John seems to be a general problem with older Gould scopes. I have a 1604 and a 4074 with waveform processor and all batteries were leakage and have destroyed the PCB.
Likely John I have placed new batteries (160mAh, NiMH) away from the pcb and the scopes are working fine.
Ralf