To know how much the gaps at the back of the lower hull are, I used digital calipers:

(.635mm)

(.61mm)

Right, then… .030″ (.762mm) sheet styrene it is. A couple of pieces glued to the end of the resin part and then clamped gently in a small vise:

Once the glue set up it was a matter of trimming the styrene to fit:

And fit it does:

The kit is a “silhouette” model; exterior only, no interior. So it’s engineered for that, not to expose inner details that are nonexistent. The lip at the right is to enable the rear (and actually inaccurate) kit part to have a strong bond. Of course that’s not there in the actual tank, so I had to remove that lip:

While the resin part was free and accessible, I also needed to drill out the towing attachment points:

 Dry-fitting the engine shows up more fit problems. The top of the plenum is in contact with the coolant fill jug above it. There needs to be space there for hoses to run, so that’s going to need to be fixed also:

Since it’s evident I’m going to need to lower the engine to get it to fit less incorrectly, I looked at the underside of it to see what I could do to get it to sit lower in the hull. That big round bit under the sump can go and I flattened the bottom of the bell housing:

Yeah…that does it:

 More fit problems (a recurring situation). You can see the right side of the radiators is lower than the left side. I checked the side pieces to see if they’re the same height and they are, so that means the radiator bulkhead is off (again). If you look closely where the radiator meets the lower hull piece, you can see they have a slight bow:

That means plastic needs to be added. In addition to the right side being lower than the left, there is a slight bow to the bottom of the radiator bulkhead that needs to be filled also. I glued plastic to where I need the additions and clamped it all into the vise while the glue set:

After the superglue cured, I sawed/filed/sanded until it fit as close to properly as it can and the bow at the bottom is gone and I cut out the access port from the lower hull piece:

Well, that was easy…