It's the vacuum shift model; when you ask for the serial number are you refering to the the number on the axle? The most visible is 128ONO.
Here's my problem, a previous owner put a different drum on the drivers side. The drive flange has 8 bolts holding the flange to the drum, it looks like any modern day floating axle; the pass. side has the original 5 bolt cover thing. (that's a technical term "thing"). Furthermore the brake shoe adjusters on the drivers side are different from the pass. side. The drivers side not be visible except through the adjustment slots so tenderly cut out of the backing plate with an acetylene torch the the old adjustment nuts where. They both work fine ,but I don't like different. I don't care about them not being original I just want them to be and work the same.
