Welcome Gary,
I recommend restoring your car to original specifications. To undertake the soft top conversion properly you'd first have to find the donor parts and the soft top frame, that might cost say $10,000 here in Australia, and will not be easy to find in acceptable condition. Then the additional bodywork could cost $10-20,000. If you're talking about just adding a soft top and not the soft top well or any other soft-top specific body parts, you will be making an ugly duckling, especially if you go with a non-W113 top.
Plenty of pagoda owners never even use their soft top. Why not restore your car to original?
Dave