Numbers on Moore & Co printed marks

Thanks to Dick Henrywood for looking at the Plaque dates page. He writes:
 
The only bit I would question is the Moore & Co. titled marks with numbers 48, 49 and 50.  You seem to have assumed they are date codes for 1848 etc, but in my experience such numbers are pattern numbers.  [...]  The North-East potteries in particular tended to use pattern numbers in their marks.  The thing in your favour is the California gold rush of 1848/49 onwards!

I've acknowledged his point by tempering my assertions on the dates page.

Regardless of whether the numbers refer to years or patterns, you'd expect their places on the Plaque dates page to remain the same.  We know that the 'California 48' plaque was produced circa 1848 in response to the 'gold rush'.  If 'Waverley 49' and 'Sporting 50' were assigned the next pattern numbers, we might reasonably expect them to be made shortly after that date. (See the Landscapes page for photos of the plaques and all 3 printed marks.)

But I'm still clinging to my assumption that the numbers are dates.  Why?  There are two versions of the 'Sporting' printed mark (and the Waverley mark also).  The first one, without the number '50', appears on Moore & Co plaques associated with the 1840s (see top two photos).  If '50' denotes the pattern number, why doesn't it appear on the earlier Sporting plaques?  I suppose it's possible that circa 1848 Moore & Co decided to number all their patterns currently in production.  (I suggest that year because, unlike 'Waverley' and 'Sporting', I've never seen a 'California' without the number '48'.)
 
Whereas 'California 48' and 'Waverley 49' apply to one specific transfer, 'Sporting 50' applies to a series.  Four different sporting transfers can be found with that number, and it appears on both circular and rectangular plaques.  I don't know enough about pattern numbering, to judge whether this is significant.

Moore & Co made other plaques with printed marks around the same time, which don't have a number.  See the 'Cuyp' plaques on the Landscapes page, or 'The Bottle' series (circa 1847). That some contemporary plaques would have numbers and others not, seems more logical if the numbers represent years rather than patterns.

The final burning question in my mind is this... if the numbers denote patterns, what happened to patterns number 1–47?  If anyone knows of other Moore & Co wares with printed numbers, please get in touch.