I have an old Bolens G174 4WD compact tractor that was made/sold in the late 1970's. This old tractor has a two cylinder diesel Mitsubishi engine that cranks out a whopping 17 hp. The thing is built like tank and does an amazing amount of work with a rear tiller or small brush mower.
When the starter went a few years ago, the local electric motor/generator guy had no problem rebuilding it. I think they can find brushes for most anything. If they can rebuild the starter of an old tractor that hasn't been sold for decades, a current Mirage should be easy.
Then again nothing surprises me any more. We live in a disposable world. The cost of labor has caused some of that. Why rebuild a toaster when you can buy a new one for way less?
In this case, new brushes are way cheaper. Glad you found them!