When re-attaching the shifter to the linkage with the long bolt, there may be some difficulty getting the base of the shifter, with the new bushings, seated between the arms of the linkage. To make this part easier, I inserted a pair of pliers between those arms and stretched them out a bit.
I also taught Masters Students at Imperial for 3 years. The molecular formula for cyclohexane is C6H12, therefore one molecule of cyclohexane contains 6 carbon atoms and 12 hydrogen atoms. The relative atomic mass (RAM) of carbon is 12.011 g/mol. For hydrogen the RAM is 1.008 g/mol. Cyclohexane's molar mass is thus: (6 x 12.011) + (12 x 1.008) = 84.162 g/mol.
The periodic table states that the molar mass of copper is 63.546 grams per mole. That means that if you have one mole of copper, it will weigh 63.546 grams. One mole is 6.022x1023 (Avogadro's number) atoms. To find the mass of one copper atom in grams, you simply divide copper's molar mass by the number of atoms in one mole. 63.546 / 6.022x1023 = 1.055x10-22 One atom of copper weighs 1.055x10-22 grams.