These do indeed look *really* good - but from Pete's description of the process it doesn't seem like it would ever be possible to use it to repro all the thousands of plastics that have come and gone in the last - what - 70 years since they started to be used?
I wonder did the old pinball companies retain master copies of all their artworks? if they did, what happened to them as one by one the companies shut down or morphed into something else? I envisage warehouses of parts holdings and hundreds of document drawers containing master artworks that could be far more easily used to recreate plastics for thousands of different machines! Is that even a remote possibility? To - belatedly - break this cycle, maybe for all new pinball machines it should be a requirement that a set of digital masters of the plastics artwork be shipped out (on a CDROM or memory stick) with each new machine.
As to the run-of-the-mill reproductions... better than nothing, yes. Also, at the resolution Pete shows above, they are bound to look bad as compared to his fresh digital ground-up recreation - however, there are few (if any) ordinary circumstances under which you would look at them so close up, you always view them from at least a foot or two away. So rather like a TV picture, look too close and you will see defects, track back 2-3 feet and those lessen or dissappear. Though some examples of straight copied plastic above ARE pretty bad, the best of the straight copies are probably - as Pete says - "good enough" for the case where a crisp re-creation is not available and let's face it, that's going to be 98% of all the plastics ever made for the foreseeable future!
Now, who wants to sell me some lovely new plastics for my 1964 "Bowling Queen" - and where is that Gottlieb library holding the master copies :-D