I had a set of aluminum spacers for my numbered series.
While they performed the task of moving the wheels out (for chains), they did wear out.
The holes where the bolts fit were not tapered to match the bolts. They eventually wore slack and then allowed the bolts to waller (not a northerner term) out the mounting holes. Had to remove the tires and tighten them up twice a year.
Eventually, one failed while on a slope and caused an usafe removal of the rear tire breaking off all but one lug bolts.
I believe the failure was caused by using a tapered shoulder lug bolt rather than a flat-shouldered bolt. If using these, spend the money on the proper bolts, steel flat washers, and lock washers.
I have purchased the steel version of spacers that has an IH part number. No issues since. Don't need to retighten.http://www.tugedge.com/p/Services#%2fCub_Cadet%2fCub_185_Lo-Boy_Tractor%2fRear_Wheel_Spacer_(Floatation_Tires)%2f011840-A%2f0118400071
Note: The picture you have shown looks like the bolts go through the rim & wheel spacer. This would be easier to retighten. The set I had was different. 5 bolts mounted the spacer to the axle, and had 5 studs that protruded through the rim and fastened the rim with nuts.