1.) Regardless of the comments of injected restorative liquids like diesel oil, brake fluid or moonshine, to make the old vacuum motor work, send your Trico motor to Ficken Wiper Service (www.wiperman.com
]). This will solve the internal vacuum leakage and get you back to square one.
2.) A quote from a VCCA member (Junkyard Dog), "I have installed about three new dual action fuel pumps on my car (since 1960) and all three were the same.....almost no wipers going up hill. With normal driving, the wipers do work better with a dual action fuel pump than with a single action pump, but going up hill is another story."
Used dual action fuel pumps can still be found and they can be rebuilt, with new hand made kits, to handle modern Ethanol gasoline. The vacuum section can be rebuilt but new (not NOS) kits can be hard to find and are limited to a few AC models (No Carter fuel pumps). Progression: AC 9126 replaced by AC 4138 replaced by AC 4666.
3.) The last add-on, period correct, solution was the Trico Electro-Vac. A little difficult to find today. It is an electric motor driven vacuum pump and reservoir that maintains vacuum level. The irony is, why add an electric motor when you can convert to electric wipers. On a side note, there has been discussions to make a DIY vacuum reservoir using a modern brake booster motor.