What is an 1879 single shot 32 Winchester be worth It has an octagon barrell The serial no is 8926 Pattern Oct 7 79?

It sounds thru your description that you have a Winchester model 1885 high wall,or low wall single shot rifle.The 32 Winchester caliber marking indicates that it was chambered in the caliber 32-20 Win.caliber.Your serial number indicates that your rifle was made in the year 1887.without giving a detailed description of the rifles overall condition;including the amount of original finish remaining.I could only say that the range of value would be between 400-1,500 dollars or more if the right individual came along.