'58 Windshield wiper saga, ideas?

[jkmhb]

Trying to make a long story short.
My '58 came with electric wipers, just the motor and transmission arms (non working).
I got the retrofit wiper motor and had to buy arms too (since it uses the vacuum motor type arms). I had to fabricate mounting brackets since I didn't have those off a vacuum motor.

Finally got all this installed and working.
I also bought new wiper arms (repros) and blades (Trico 15" classic series) from Classic Industries - the latest batch of problems begins.

The Blades fall off of the arms. They won't stay on at all.
The arm on the driver's side, slips when the wipers are on (the cone turns but the wiper doesn't and makes a grinding noise).

Any ideas? TIA.

These wipers are taking way too much time!