I don't think hyping it up in the same way as boxing will work. Firstly the coaches don't want it as it gives the opposition a leg up (there's a reason other than good decorum as to why coaches generally don't slag off another team) and club's management don't want it because you look daft when you lose.
What I think could be done is the introduction of "heritage" rounds. Each week for the first 12 rounds of SL, a different team would have their "heritage" (or whatever you wanted to call it) round.
Each club would produce a heritage kit which would obviously be worn in any heritage games they played in.
Maybe designate a heritage decade each year so that all clubs are roughly similar?
Each club, when the fixtures are being organised, could pick their opposition for their heritage game.
So if it was taking place this year,
Say we designated the 60's for this year. So all clubs would produce a heritage shirt from the 60's and, ideally, pick an opposition who they had a big/important/memorable game against in the 60's.
So for instance Leeds could pick Wakefield with the Watersplash Final.
It gives clubs some extra basis from which to market that game and we'd have the RFL additionally marketing each clubs heritage round. So the entire focus of the sport for that week is on the club whose heritage round it is. Obviously get the game on Sky with some decent videos for them to market the game in the week too.
