nope!!
this appears to be Sowerby Registration 352137, and described on the original factory drawing as a 'vase' - unfortunately, as usual the drawing lacks any indication of dimensions, and you've not included any with your post. Oddly, and I may have this all wrong, and no doubt Fred will put me right, but - pattern 1486 in Cottle (page 111) shows two pieces each with the same floral pressed decoration - one is a milk/cream and the other is a container of some sort, probably a vase - but neither piece appears to have any connection with the surface pattern/decoration of this small item - so is there an error somewhere?
I can't see any tortoiseshell in either Cottle or Sheilagh Murray, who says of tortoiseshell as ................ "The last named is extremely scarce."
C.H. appears not to show any pieces.
Ray Slack writes ............................. "In July 1882 a summer novelty was introduced under the name of Tortoiseshell Glass, and was reported as 'very pretty and attractive. It's imitation of the real shell is striking, and being brought out at a popular price it must have a large sale'.
Slack also seems to have been unable to find this colour to include in his book.
So the short answer is that at present I can't find a colour picture of this variation with which to compare the piece shown here - it certainly isn't gold 'Nugget' - hopefully Fred will have more information on this one. Casting perhaps an unfairly critical eye at the colouration of this piece, it does appear that the 'tortoiseshell effect' is only partial, and has failed to appear on the sides of the glass.
In his list (page 103), where he cross-references factory and Reg. Nos., Cottle links Reg. 352137 with factory pattern 1472 (pattern book IX page 9) - not pattern 1486, and if you look in Cottle - page 111 - there is an example of factory pattern 1472, and the piece shown does agree in surface decoration with your item, so would seem that the correct factory pattern should be 1472.
In case it's of interest, there were five Registrations from the factory on this date ......... Nos. 352133 to 37.
Kew archive image now attached for 352137.
However, an important find I'd suggest.