[chem_man]

Attached is a pdf with a couple of pages related to the jack. The picture on the first page should help.

 

[chem_man]

OK. I ran across another image that shows things a little better. Hopefully it will be of some assistance.

 

[chem_man]

Just one more of the many minor differences between the EXT and non-EXT versions.

I think you are correct about the rear HVAC being only an HAC system.

 

[chem_man]

According to the parts list that goes along with the diagram, Part #1 is some kind of retainer. It's been so long since I looked at it I cannot say if mine has one.

Likely, one end fits under a lip on the floor and then you flip it up and over to kind of lock it into place - just a wild you know what kind of guess.