: Using a safe solvent (historically dry-cleaning solvents or mineral spirits) to remove old, gummed-up grease from the spindles and tangent screws.

Do not use a phone camera. Use a flatbed scanner with a lid.

Repacking a vintage is a meticulous process focused on restoring smooth mechanical movement by removing aged, hardened grease and applying fresh lubricants. 1. Scope & Preparation

"Hilger Watts theodolite" manual filetype:pdf "Hilger and Watts T1" manual repack "Microptic theodolite" adjustment manual Hilger Watts T0 user guide restored