I can see why it took you three hours and for the precise detail you have achieved in the hoof hair which was blown orioginally I think you did well. I would suggest a little more time using a quite simple process of duplicatng what you have and extending the grey iron wall to cover the truck and fence and then erasing it where the horse is. Took me half an hour to do that but to get the detail of hoof hair easilly could take the otheer 2.5 hours with experimentation.
This perhaps answers the crit of what you had ... what you might choose to do in a further quarter or half hour having done the hard yack already

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EDIT ... forgot to mention one blurrs the top layer to required degree and I also use the blurr tool [ like a paint brush] on the sand behind the horse. I use PSP and worked from your original and first step was to adjust using curves as an adjustment layer. Don't know if PSE has comparable toolds