I don't know who Dave Smith is (or, rather, I know who about a dozen different Dave Smiths are, given how common a name it is), so I can't claim any insider knowledge, but I think that this seems a really good idea.
I'm fairly ambivalent about Open Access etc but here we've got a line (north of Skipton) that's relatively lightly used most of the year (bi-hourly Sprinter) but gets huge demand in summer months - so something to deal with the increased number of passengers over the peak period seems a no brainer.
Obviously this forum is never going to agree on the "correct" type of stock for it (or the right colour of the locomotive, or the seats or...) but I think that a 47 and a few coaches sounds perfectly acceptable.
Let's face it, a lot of people will only be bothered about the A-list bit over Ribblehead, so it makes more sense to use your one train to provide a few journeys over that, given that there are good connections at Skipton for Leeds/ Bradford.
Sensible.