As stated ., i am by no means an expert here but i am totaly unaware of the "wrist pin installer tool" you describe .? If the con rod bushing was sized correctly you should be able to insert the pin completely with hand force only and the piston/pin/bushing connection would rotate freely with little to no resistance.
My manual states a 0.001" or less , pin to bushing spec.
I suspect a undersized bushing might be the culprit.?

 

The piston pin is a slight press fit through both sides of the piston, not the con rod. As you state, the pin has a slip fit through the properly fit rod bushing. There is a tool make to insert or retract the pin through the slight press fit at both sides of piston were c clips are located. I found out after my costly mistake that you can heat the piston with a heat gun and the pin will also easily slip through both sides of piston.

 

Gotcha busterman ., i have done this procedure but not on Harleys . I was unaware that the pin to piston fit was so tight that an installation tool was needed . My manual dosent describe this either .?
So, now its replacing , reaming and honing another rod bushing and all the crap that goes with that . Sorry about your troubles there.
I see there is a special fixture/tool to install the rod bushing , if it were me i would purchase 2 or 3 bushings because they are cheap and fabricate a simple bolt /nut /spacer tool to install the bushing . If you mess up a bushing , try again with another.
I would think that , if you are carefull to ensure the bushing is positioned properly before you begin inserting it into the rod , there should be no problem here as long as you dont cause any axial stress to the rod big end bearing as you procede.?
This is my old school 2 cents only as i have found that " special " tools etc. are rarley needed .
If im off base here , i hope the other bros. will chime in .