Larry K. I don't agree with Hydro on much, but I have to agree with him on your PTO rod. I've owned my #72 for soon will be 38 years in a couple weeks and have NEVER had the grill casting off it, but have rebuilt and installed a 10 & 14 hp Kohler, so it should be basically identical to your 105.
Just humor Hydro and Me, engage your PTO lever, slightly pull the lever out away from the dash and let it fully forward till it rests on the tractor frame, should take about a tenth of the time it takes to read that sentence. Loosen and remove the top mounting bolt on the starter/generator and slightly loosen the two lower bolts, remove the belt from the S/G pulley, pivot the S/G away from the engine and let it rest on the right frt tire.
You should be able to install the PTO rod in the front lever and angle it back to rest on the S/G bracket. Attach the rear section of the PTO rod, join them with the turnbuckle, swing the S/G up into position, slip the belt on the pulley, install the top bolt and tighten, tighten the two lower bolts. Adjust the pto clutch clearance as per manual with the turnuckle, snug up locknut. Even raising the hood for this job is optional. Loosening the turnbuckle to get clearance between the fiber button and PTO clutch is how I've always installed mule drive belts, snow blower drive belts, even sprayer pump drive belts run off the pto. Been a few other front mounted home-made attachments that I've built and run with the PTO too.
If the above doesn't work on your 105 then something is different on it. Even the 129 I had for 15+ years I used this procedure on. Harry and I will need pictures