As I recall seeing them, the original MD Roadrunner goes back to about 1988/89 - prior to that it was a mixed batch of home made/manually driven, bar mounted "boxes" - for the mostpart.
The MD - as shown on the photo's tREV posted of the BYRD Yamaha's and Lucky Strike Cagiva's of the day - was really the first commercially available electric driven roadbook roller (and it's internal rubber o-ring driven design has been largely unchanged since then).
Back in the day the only other readily available (commercially sold) alternative was the venerable Acerbis plastic map holder (white plastic).
Other than that most of the RB' rollers I've seen from back in that period were either individuially fabricated (or very limited hand production line) versions of manual (sometimes el driven) holders usually fabricated in light guage aluminium or stainless steel.
What did your DR BIG have on it back then TT...?