All tell you is that newer than 1992 year. You go to MTD site click on tillers troy bilt may find something out
12181 1206020 your serial number does look like troy bilt number newer number had 12 digits.

all decals and a owners manual have garden way on them,would mtd use that for a while?

tried mtd with ser#.and came up with 1999. thanks for the help