Took the mystery Mrazek for a ride yesterday, and it was really cool. I thought it rode really well.
Had to put the seatpost way up, which was a little concerning considering how cheap it was. I could put a long Thomson on it, and it would actually fit me pretty well, but I think it would look a little bit desperate. Anyways, interesting find, and still trying to figure out when it was made.
As found, estate sale.