thanks to both for your replies.
Unfortunately for us, nowhere in Slack or Thompson or the images at Kew, is there any cross referencing between Registration Nos. and JD pattern Nos. - and it's this omission that makes life difficult.
When he was active, Raymond Slack had more written information than anyone else - his work appears accurate, usually, although I'd agree that he does seem to be wrong in suggesting that his pic No. 4 was Registered on 08.08.1873. Slack must have had access to JD's pattern Nos. in some form or another - unfortunately, his archive was dispersed (unsatisfactorily), and I doubt that he'd now remember the details, but might discuss with him. Do people know where he might have sourced such details as JD pattern Nos.??
I now have many hundreds of pix from the Kew Representations books for the Board of Trade 43 series.........43/60 - 43/61 - 43/62 and 43/63 - four groups covering the period September 1842 to January 1884 - and some of these pictures are, for me, very recent acquisitions, and which I'd not viewed until today.
I don't have a picture for every Registration - more a selection relating to GMB interest (excludes bottles - so don't ask me for a Kew pic of a bottle) - but I should have pix of all tumblers/stemware/drinking glasses, and I've split each of the above four groups into two parts, in essence separating drinkware etc. from 'other glassware'............thus giving a total of eight sections................the thinking is that it'll make searching easier!
Have now looked at the section for tumblers/stemware under ref. BT 43/62, which covers the period October 1870 to February 1879 (the JD period), and can confirm that I have Kew images for Registrations 274962 and 274963.
Have also looked at the corresponding 'other glassware' section for the 43/62 group, and see that I also have Kew pix for 274961 and 275756. Watermarked pix are now attached for each of these four Rds., although it doesn't help to with identifying JD pattern Nos. with Rd. Nos.
Although BT 62 covers a period of something like nine years - including the entire life span of the JD factory (1873 - 1876) - there are remarkably few Registrations for drinking glasses/stemware - with only seven goblets, and these include the two for JD. It's possible that some additional Registrations for drinkware are amongst the 500 or so 'other glassware' pix which I've not yet had a chance to look at, although bearing in mind the utility nature of most of these goblets, their absence may be simply due to a lack of Registration in the first place. For example, of the 15 or so pressed goblets I possess, this one is the first that I've found which carries any sort of mark
Fred's pattern 256 is definitely No. 3 in Slack's book pic, but is missing entirely from the Kew images, so as you say it may well be an item that was never Registered.
Re pattern 258 - I'd agree with Neil and believe we can say reliably this corresponds to 274963 - confirmation from Rob's picture and the attached Kew image (assume also there is a No. 259 on the goblet itself).
I've noticed that it is possibly easier to differentiate these goblets by looking at the design of the stem............. pix of bowls are sometimes lacking in sufficient detail, making id unreliable.
I've only just started looking at the Kew pix for goblets etc., and if I find further information on JD I'll post promptly..............meantime hope the attached are useful - and hope I have all the above details correct.
thanks again to both of you for the replies.