The best investment I made in my first restoration was joining a marque-specific club before I started. The knowledge, the parts connections, the willingness of experienced members to answer questions — it compressed what would have been years of trial and error into months.

The second best investment was buying the factory workshop manual and actually reading it before I started disassembly, not after. The manual tells you what goes where, what torques are required, and what special tools the factory used. Improvising what the manual prescribes is how you create problems that didn't previously exist.

The third best investment was a good digital camera and the discipline to photograph every step of disassembly. Reassembly is much easier when you can review how the thing came apart.