Is It Real or Memorex?
Okay, Ladies and Gents, here's the final say, okay (I hope):
From our esteemed reference, a product originating from the minds, fingers and, um, whatever else of those who find time to spend here when the lawn needs scraping:
Standard Catalog of Smith & Wesson, 4th Edition, by Jim Supica, Richard Nahas and scores of S&W owners everywhere:
"Model 645: 2nd Generation .45
"Early guns have an alloy backstrap, later guns have a plastic backstrap." (SIC) pg. 358
"Later" is inadequately described within the pg. 348 reference, though referenced herein this thread are "12 prefixes" for the Model 645.
My still-boxed, unfired 645 has a "TAY" prefix, later than many yet earlier than still others. It has an "alloy" backstrap, as referenced, again, on pg. 348 in SCSW4. Thus, no real clue as to when or what "later" 645s are being referenced with regard to plastic.
So, Louie, you just keep on spreading that fact but, perhaps, with an added caveat about "later" so that, well, some other folks don't go into conniptions.
Later. (Which, BTW, is my standard SO.)