Now for day two. We started with more dimensioning, but this time I was able to use my completed side to draw out my second side. Once the completed side was clamped to the top of the untouched 4x8 sheet of MDF I traced it so I would know roughly where to cut. The idea then was to cut close to this line, within about 1/8 of an inch so in could then be routed using the finished side again as a template.
The picture below shows the traced on 4x8 sheet with several cuts. We used the circular saw (dropped in) for the longer cuts and drilled holes where we needed to get the jigsaw blade in. This allowed us to use the jigsaw for less cuts as it is much slower, but better for tight corners.

Here you can see the piece fully separated from the rest of the sheet and ready to be routed to match my finished side.

Once we had the two sides lined up and clamped they were ready to be routed. Using a flush mounted cutter on an arbor with a bearing we were able to easily match the two sides up. A couple of notes here : Yes my Dad cut this as I have little experience with the router. This stuff got
everywhere! Seriously, even with me following along closely with a shop vac in was still very dusty in there. Wear a respirator or mask of some sort!

Just a couple of other tips I thought might be helpful to others. You can see in the previous two pictures we totally forgot to cut the 45 along the back of the sides. So later we had to re-clamp those two pieces together and cut that 45 using the circular saw and then sand it clean. Even though this ended up coming out okay....try not to skip steps as in other cases in might really screw you.
My inside cab dimension will be 26" and since each of the pieces on the inside needs to match for the cab to be square we decided to cut each 26" dimensioned piece 1/8 of an inch long and then route them using a 'master' piece. This worked out nicely as all of our interior pieces now have the exact same dimension. This did add a significant amount of work and mess, but in the end I feel the fit will be much cleaner.
As of tonight I've got my t-molding on order with the arbor and bit I'll need to route in the slot.
More to follow hopefully next weekend!
Honkyharris