thanks Fred - so obviously, as you say, the original Registration for this design appeared on a sugar and not a butter dish, showing it was a protection for decoration rather than shape - factory decorative pattern No. 1970 for all pieces, whatever the shape. With your experience and knowledge of these things, do you think this change of approach by the factory, whereby they became less concerned with Registering shapes, perhaps - and concentrated more on decoration such as this one for example - was something that occurred more frequently after the demise of the lozenge period? Rd. 91432 was Registered some four/five years after the end of the diamond period - and I suppose to some extent you could argue that there is a limit to the variety of shapes of sugars, butters, vases, etc. etc. that can be invented, and perhaps better to concentrate on decoration. Maybe some time around the early 1880s Sowerby considered they had possibly exhausted the range of potential useful and practical shapes.
I would of course have included the National Archives image for this Registration, if I already had it, but for items post 1884 I have to make a visit, usually, to find them, and will include this one on my next trip to Kew, and post in due course.
Yes, thanks to Dirk's lessons in photography, my pix have improved, but the horizon line is not ideal and although I'm not entirely sure believe my mistake when bending the Perspex was to create the right angle with too sharp a bend. 3 mm Perspex isn't easy to bend and I recall it took ages with the heat gun - if doing this project again I'd be inclined to bend the stuff over a curved former to avoid this unwanted horizon line appearing in the pictures.