M26 option on Road Runners in 69 and 70 not sure about 68

In 68 the RR was pretty basic, with the popularity the 68 received for the 69 model year they added lots of options for broader market appeal

http://www.mopar1.us/6971codes.html

http://www.moparts.org/Tech/Archive/misc/11.html

These seem to agree with what I remember. I have only seen 69's with moldings back in the day, a convertible a friend bought off the original owner in 76 and a high optioned A/C car, both were very original, perhaps they could have been dealer installed?

Then there's the never say never Mopar rule. Need to see a window sticker or build sheet with the code on it. All I have on file in that era are WS, WP, WM'S AND XP29's, no Plymouth build sheets