Last week bought from fellow member the badger/horse hair brush and arrived in my hands on Monday. Have tried it out three days now and just do not like the feel or backbone. I knew it was 50mm loft and smallest that I own but surprised of lack of backbone. I had one 24mmx65mm Whipped Dog silvertip in my den waiting for my custom Amboyna Burl handle to come in and decided to replace the badger/horse knot with the whipped dog.
Used steam to remove the knot, then dropped in a 6mm cork plug in so I would get a desired loft of 53mm. I filled the hole with expoxy then seated the knot and let the brush set. Final measurements of the this brush are handle 54.6mm, loft 52.5mm and diameter of the knot 51mm.
I forgot to take a photo of the actual brush before I replaced the knot but you get an idea from the photo below. Knot on the left is the mixed badger/horse and in the photo is actually bigger in diameter since it is not dropped into the handle. I would guess you could subtract 10 from the diameter and this would be closer to the actual width of the knot of the original brush.