I added some few things that I think necessary.
Tachometer - to help me monitor my engine’s performance and efficiency.
I always stay around 2K of RPM. to conserve gas. :)

I have insulated the air-cleaner to provide colder air intake for power. Then my DIY "Oil Catch", made from pepper dispenser - to prevent oil from PCV going in to the intake for clean burn and prevent the oil from contaminating the spark-plugs.

Parts and Maintenance - Denso Spark Plugs, Distributor Cap, Toyota Tension Wires.

And most important… Electronic Pulse Generator for HHO or Hydrogen boost.

UPDATE: Dec. 20 2008
Old but original Corona's Denso air-con cooling system parts.
Flushed, Cleaned, and Reinstalled.

Adaptor mount over the original bracket for the Sanden Compressor rabbit ears bolting holes.
If others can do it... Let them do it... lol... :)
The green cloth was soaked with water to cover the fuel filter and fuel lines while welding few spots for the adaptor before a good finishing weld job.

Test fit...
Sanden compressor, given to me by my brother in-law.
Hmmm... Nice fit.

Ahhhh cool breez....