Well after looking on-line there seems to be one guy that does running board restorations www.runningboardrubber.com. Can you say PRICEY??? I'm sure you can get running board mats for your standard models, but I have a 37 Nash Lafayette, so just ordering a made to fit cover is not an option. So.... I did a search here on the HAMB, and all though there are many suggestions (Lowes and Menards rubber mats, truck bed liner, vinyl tuck and roll) actual pictures of the final product are few and far between. I don't want to go with the smooth look, so any pics of actual restorations with the above mentioned materials would be great!
There's a fellow in GA who does re vulcanization of running boards. Folks say he's excellent. Name is Huntley Acuff. Read about it here. http://www.fordbarn.com/forum/showthread.php?t=11311&highlight=running+board
The running board rubber items are darn hard to find. It seems as if stuff like commercial floor mats, stair runner rubber and such are all pretty shallow, straight grooves. Short of buying the pricey repro things you mentioned, I don't know where to look, either. I could use some correct stuff for my Plymouth, which is inside the doors....but it has a unique pattern you can't replicate in the general marketplace. Not any help......just agree it's difficult.
This place: http://www.restorationstuff.com/RSC28.pdf Has running board matting & trim I haven't seen elsewhere.