Check out the B stock I got my M80 and M22 they are flawless, The quality levels are great even the most tiny of details go in to a perfect product.
For the last year I thought my M22 had possibly a color flaw now noticed a ding on bottom front corner, but very small Eg. excellent rating. That took forever to find!
Plus check into used or your older amps will make M80 the star of the show newer tubes on the sansui would even shine