Let me try to explain what the drawings represent. You will have to pay careful attention here because the drawings are VERY sophisticated - and thus obviously drawn by Mr C, the draftsman – for no “novice” or “naive” person could have produced them.
Here I highly recommend that you have a picture of the drawing in front of you as you read this and the following explanations – I would also recommend you obtain a physical representation of the object – such as a saucer from a saucer and tea-cup set… I would suggest you obtain two and tape them together face to face, but failing that, one will suffice – (got all that in front of you? Right, we can proceed):
The upper drawing represents a circular object seen from below and at an offset angle.
Now hold your saucer (right way up) at arms length out in front of you – with both hands. Adjust the angle of the saucer so that it matches what is seen in the upper drawing. Now imagine the edge of your saucer is a bit thicker and there is a small fin poking above the left side. See…it matches!
The witnesses described a circular object and the draftsman who created the drawing represented that circular object on a 2-dimensional surface as seen from a particular perspective – that is, from below and at an offset angle.
Now the second (lower) drawing. This is a MUCH more sophisticated rendering of the circular object.
Invert your saucer and place your left index finger over the upturned base (to represent the fin). Raise the saucer with your right hand to eye level (with your left index finger still in place). Adjust the angle (by rotating the saucer – left side toward you) so that the upper left surface of the saucer appears as a small sliver behind your index finger. You should now be able to see a large portion of the upper right surface in front of your index finger and a small sliver of upper left surface just behind it (just as represented in the drawing!). Now, NOTE the direction your index finger is now pointing – for THAT is the direction of travel as represented in the drawing (and that is why the directional arrow in the diagram seems to be pointing slightly down – it is meant to represent the object travelling into the page away from the observer)
Okay… now (if you have not used two saucers taped together) imagine that second saucer underneath facing the first and imagine the edge a little thicker. See…? It represents the drawing pretty closely doesn’t it?
NOW can you see how your “blimp shape” is a complete misinterpretation of what the drawings actually represent? If you do not, then you have simply failed to conduct the experiment as outlined.