[Richard]

I m going to think out loud here for second. Matching the dash picture with the underneath picture identifies which switch is what. So that makes the switch in the lower left corner the master switch. I am going to assume that master raises or lowers all four corners simultaneously.

The diodes are the key to understanding how this could work. Let's just focus on the up motion for the discussion. The down motion will have the same logic just wired to down solenoids and the other side of the switches.

For the Master up to raise all four corners it must be electrically connected to all four raise solenoids. However this connection would also mean that any of the individual corner switches when activated would power all four up solenoids. The way to prevent this is the use of the diodes. So the siamesed wire that connects the individual switch to the master switch has a diode on it to keep the power from the individual switch from passing to the other three solenoids.

I am going to guess that you have another bundle or two of these diodes buried in the rats nest.

Here is what I can make out from the pictures on wiring coloring.
Orange/black is 12V +
Brown is RF up
Grey is RF down
Black is LF up
White is LF down
Blue/white RR up
Yellow/? is RR down
Orange/white is LR up
Black/? is LR down
Red goes to travel solenoids

Hope this helps. And looking for input from the electrically inclined gurus. I'm a plumber not an electrician.