Added to that was a labor dispute involving the LIRR car maintenance workers re: who was going to do the warranty work; LIRR workers or the manufacturer's (Budd Co.) personnel. After Governor Nelson Rockefeller finally intervened a settlement was reached and the work finally got done. By about 1973 the entire LIRR M-1 fleet was delivered and up and running.
![Very Happy :-D](./images/smilies/icon_biggrin.gif)
BTW, the M-7's on LIRR have broken in much more successfully than the M-1's did, partly because LIRR tested them at length before starting them in revenue service. And they had more time to do it, as there isn't quite the replacement crisis with the M-1's now as there was with the 1920's era trains in 1970.
![Wink :wink:](./images/smilies/icon_wink.gif)