Here's my $100 pile of rust.

To the naked eye it looks pretty bad, but it was worse!

What's left of the Willys decal

I finally got the back off.  Someone welded a steel patch over the mounting stud on the right.

This is where all the Harrison heaters break.  It's very thin sheetmetal and a small reinforcement in the rear of the mounting stud.

After removing the plate that was welded on, I marked the area I wanted to cut out.

Here I made a template of the hole so I could transfer them once the new piece was welded in.

Here the new piece is clamped in place...

And here is the back with the sheetmetal replaced and a new stud installed.

Stripped and ready for paint!

The fan was taken apart and cleaned and painted.

I don't think these knock-outs were on the 2A's (anyone know?), but they are for the Harrison heater.  You won't find these on repro bodies!

The heater core is leak tested underwater with about 20psi of air.

Any small leaks were repaired with some epoxy.

The core and the fan are installed.

A brand new heater is ready to install!

The unit is pretty difficult to squeeze under the dash.  I ended up cutting about 1/2" off the heater core tubes to get it in.

The heater fits great in the holes already provided from the factory.  I used a nice retro rotary switch I found on Ebay to power the unit.