I found an old brush and a big mug that came with it. I gave that to my grandpa to build up a nice lather. However the question is, is this horse hair? I've only felt boar and synthetic so I don't know anything about badger or horse hair. Another question. I really like the handle and I wanted to know how I'd restore the brush and add new hair to it.
Not necessarily. That looks like boar to me, also. Replacing the knot is easy. Cut it out, smooth the hole, glue in a new one. If I can do it, anyone can. http://theshaveden.com/forums/threads/finally-jumpin-in.34103/
Yeah, that's a boar. Reknotting a brush is not rocket surgery, so you should be able to do it if you want. It is a nice looking brush.
If by brown in the middle you mean this; Then yes, this is a boar, but it has been dyed to resemble badger hair. Undyed boar hair brushes don't have the stripe.
Yip, that's boar in a pretty darn nice handle. If you don't like the knot, replace it. In many respects, boar can be superior to badger despite being more affordable generally. It always upsets me that manufacturers feel a need to dye boar hair in order to make it look more like badger.
Use calipers to measure the inner diameter of the hole in the brush. Measure in millimeters as that is how knots are measured. You may see two numbers when you look at brushes, the larger number will be the loft height of the knot, the smaller number will be the diameter of the base of the knot. A knot set deeper into the handle will give you a shorter loft, naturally, and make for a stiffer brush. Start getting higher lofts and you start getting floppier brushes, which you may or may not prefer.
Using a ruler and a good eye can give you a fair estimate of the knot size too. Typically, those older brushes have something around the 20mm or maybe even 22mm knot size and can often be widened out to something like the 24mm knot size max (if desired).
Looks like an old spice brush. That model was usually included with the ceramic old spice brush and razor stand. They are fairly common.
Probably boar, but it looks alot like my bestshave.net #6 horse(?) hair knot. Many people claim the #6 is actually boar, I don't know, but it is a nice knot, makes great lather and lots of it.