I vividly remember the 'Venus Transit' event of 2012. Bjørn J and I shared great adventures before and after the Transit.
The weird look of the front assembly of the 1200 mm Nikkor was due to the need for putting on a solar filter *and* keep light leaks away. When I assembled the bits and pieces, I discovered the diameter of the filter was slightly too small to allow the filter to slide over the rim of the lens barrel. Thus, danger of light leaks was imminent. I found that the front casing was hold in place only by a small grub screw and managed to get it out, thus removal of the casing was possible and thereby allowing the filter to mount safely. Not what you want to discover immediately before the unique Transit commenced, though. I got my shots so all is well that ends well.
Also nice to see the moderately sized Sachtler in action. The fluid head usually is atop its bigger brother.