More sad hours spent on Excel reveals that RR came out well ahead of PW on the DC-10/MD-11/L-1011.
In so far as I had thought much about it, I suppose I had assumed that RR would be in third place. (Their habitual position, it seemed, prior to the launch of the Trent series.) In fact, there were 896 Trijets built (including the KC-10s for the USAF). Of these...
522 had GE (58%)
250 had RR (28%)
124 had PW (14%)
Perhaps more to the point, the clear winner was, of course, GE.