Here are some links to repair tips and reference material.
vintageTEK Museum Product Repair
468 Mostek MKB36000 ROM Repairs
7854 Mostek MKB36000 ROM Repairs
Circuit Descriptions with Chuck Miller
Dallas DS1287 Dead Battery Repair
Fundamental Electronic Concepts for Oscilloscope Use and Maintenance 1956
Keytronic Capactive Keyboard Repair
Primer of Waveforms and their Oscilloscope Display 1960
Repairing Plastic Knobs and Gears
Troubleshooting Your Oscilloscope
Using the Oscilloscope as an Instrumentation Maintenance Aid 1958