A DPF of the size needed certainly could not have been built in the 19th century. The speed and power of capacitors was not available. Lots and lots of engineering must be done to go from the idea of a capacitor to those that we are using right now. Same with other technologies. You could probably have explained a steam engine to an ancient Roman engineer but the Romans could not have built one. It takes a lot to have the tolerances and sealing that makes a steam piston actually work. (In historical fact the idea of the steam engine came centuries before the reality.)
However, if adequate resources had gone into not only DPF but all of pulsed-power technology from the 1960’s on, development could have been vastly sped up. No doubt with that sort of broad-based program, we could have been where we are now 25 years ago. If you can imagine the US government making controlled fusion the sort of priority they made the H-bomb, maybe that would have been 35 years ago. But that would have required a very different political reality.