I got in touch with Victor yesterday. His answer was to run the anchor rope over the forecastle. He shared their research on the topic.
One model from NMM had the Hawse hole too low to be realistic for the height of the forecastle from lots of line drawings.
One had a Hawse hole that was in an ok position but wasn't supported in other lilne drawings. It also has that bracket against the bollard timber, there are similar fittings in the others.
Here's one with the rope being rove through a bracket on the bollard timber or thereabouts, hard to see from the picture.
And finally, a painting with it just laid over the forecastle.
I have a hard time believing that it was allowed to wander around on the bow while the anchor got hauled out, but without more details or examples of that bracket at the bollard timbers, it's hard to add. The bow doesn't come together like the illustration and models for this Hoy, so it would be a lot of guess work.
Someone posted information to this thread on using a bracket near the catheads, I saw it in my notifications by email but it looks like it has since been deleted. I would be interested in seeing it again.
So their conclusion was to represent it more like the painting. It isn't satisfying to punt like that but it does avoid an apocryphal bracket, it's probably the best choice given the info avaiklable. Modelship Dockyard has obviously done a nice job researching a work boat that is typically poorly documented. The only reason there are as many images and drawings as there are is because of the long use of the craft in different periods, making information and designs scattered over decades.
Barring new information, it's over the forecastle.