I believe he did have one Holland Woodward in 6.5X53R (256 Dutch). That's the one with the unusually long block - sold at auction a few years ago and we discussed it here back then.
His 303 might have been sent back to H&H to be re-barreled. I think I've read about that in some book before.

As far as I know, George Gibbs was the only maker to size the Farquharson actions for medium and smaller cartridges.
Jeffery did build a few Rook rifles on the small Lemmerzheim (sp) actions but their 303s and 400s were all on the same action. Of course the few 600s were on bigger bolstered actions.
Gibbs 303s and 256s were built on a smaller action than his 461s.

As Tinker mentions above, that's the problem with the Ruger No.1 and No.3 actions - one size fits all - so you have an oversized and overweight action for Rook, varmint and handgun chamberings.
If Ruger had just made a 30% smaller version...

So, back to Rigby, I'm sure that with modern CNC machining, they could easily offer a scaled down version for lighter rifles. Will they? I very much doubt it but hope they do!