The Stone Roller monument commemorates the construction of the first patented concrete filled railway wheel stone roller used to make the land arable.
There is a plaque at the posted coordinates with two sets of numbers. Let ABCD be the first set of numbers, and FG-H-IJKL be the second set of numbers.
The cache can be found at:
S 35° 22.(G+H)DJ' E 139° 33.KF(C+D)'
Decimal minutes checksum = 35.
(Add up the six numbers to the right of the decimal point to confirm)