Yixing type vintage Chinese redware clay tea pot, inscised horse chestnut herb

We know very little about Chinese antiques or vintage, but I loved the horse chestnut design of this little red ware teapot!

I don't know it's age or exact origins and I can't read the little round mark or the characters. I do know that this is NOT in good condition, it's cracked and repaired - please see photos. It measures about 4 3/4" x 4" x 3" overall.