Harm,
I have all the "windows" blocked off with styrene, so I won't be doing anything other than attaching the Royal Models resin flappe via Epoxy. They will all be closed.
I felt that it was necessary to use Tamiya putty & Mr. Surfacer 500 for 2 reasons. The back of the 234/1 (along with all 234 series) has a hatch to access the engine. The Italeri kit has that molded flush with screws set in along the perimeter. The hatch is on the surface and there are no screws anywhere that I can tell so I filled all that in with Tamiya putty, sanded it, then went back in with Mr. Surfacer 500 to fill in any scratches I may have left and then went over that with steel wool.
This is the 2nd 234 kit I have built and although the 234/1 was the last to be released by Italeri - it shares the same flaw as the 234/2. You will see that there is a gap between the hull & the top plate (the one the turret mounts on).
Here are some VERY CRUDE drawings I whipped up. The red line is how the top fits when you put it in place. The space between the red & black lines is exaggerated, but it IS noticeable.
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I filled that area in using the same materials and I shaped up the sides of the full a bit to make sure they were flat - the left over "putty" tells the tale - they were not flat.