When I have a difficult image, I start out with relatively inexpensive RC paper. Being honest, I probably print on RC first the vast majority of the time. It will be a lot less expensive to experiment with the above good suggestions. Of course the final details of the exposure will not be the same, but you will fell much better about the pile of prints needed to get to your final image.
A burn of the top half of the print with oo filter may darken the whites without affecting the blacks.
My comment was that if there were no clouds and as the author of the the work he felt clouds were needed to convey his thought that would be a way to do it. While Uelsmann's photography may not be everyone's taste if you get the chance to see actual images up close and personal you can't help but to be impressed with his printing skills. Remember he has been doing that well before Photoshop and personal computers became mainstream.
Photography is communicating a visual representation of an idea, a message or sharing a vision. Burning, dodging, split contrast printing, toning and whatever else one may do to make what they feel will best convey their art are all manipulations to the original capture. Creating an image with PS or Illustrator etc are just other mediums. Pencil sketches, charcoal, oils, watercolor etc each have their place and appreciation. Why get hung up on film or digital --- take each for just a different form of expression.
I try to understand how long time I would need when flashing the paper, or burning the up half image without compromise the blacks.
Based in this test, it looks to me that I would need expose the paper for at least 3 sec, or burn the sky for 3 sec, in order to make the sky a bit light grey.
But I have a strong feeling that I am look at it in a very wrong way:
This 3sec dodge is what I actually did to come up with the result I posted before.
You have a good horizontal demarkation at the fields and distant tree line. Dodge below that and try a grade oo burn above it. You will find the tees and branches do not change but the sky will.Ther is a good chapter on this in the Way beyond Monochrome book.
Thank you... I will try tomorrow.