Ever-Ready model C40 ("Sterilized". Really? People buy it because it's sterilized?!?) I can't tell whether the company is still in business, so you might have to Google "ever-ready c40 shaving brush" and then shop Etsy/Ebay. They're also on that BadgerandBlade website.
I'm not sure that "badger hair" would pass the blindfolded use test against an old toothbrush or a sponge, but then I only shave twice a week.
I bought my C40 in 1984, used it through 1992, stored it for 20 years, and recently put it back into service. Looks the same as it did when I bought it.
You might be spending too much money on the bowl/soap and not enough on the brush. I use an old prescription pill jar filled with Zest soap scraps.