The older Shimano freewheels have a smaller spline pattern and cannot be removed without first removing the axle locknut and spacers to gain access, then using the F/W remover. later on Shimano went to a larger spline pattern allowing the use of a thin wall remover which fit over the axle's locknut and spacers.

BTW- on some axle sets you may not be able to remove the locknut working form the right side, and might have to remove the left cone and locknut then slide axle out to the right.

If you plan to replace this freewheel, I suggest you remove the locknut and spacers (or the axle) then let the LBS do the job which will cost less than the tool, otherwise if you want the tool, I have a few and can sell you one at a low price. email me at info@ the site below for a quote.