I give my thanks to Alan.
The blade is just shy of 13.5 inches. The width at the base of the blade where it meets the ganja is about 2.1 inches. Entire keris in sheath is about 17.7 inches long.
As to the Kelantan/Terengganu attribution, I must say that the sheath is very similar to some Sumatran examples. I attach pictures of 2 of the closest types for comparison.
Kelantan/Terengganu versions of this sheath form tend to be proportionally flatter than their Sumatran cousins. They also tend to be "boxier" in form, especially on the left-hand side (the lower left corner is more pronounced, less rounded). The 2 tips of the sampir (daunan) also tend to curve inwards to a lesser extent. You may have noticed that the first Sumatran keris seemed to be boxier, but you'd also notice that it is a lot broader - too broad for N Peninsula. This type is closer to the 'chieftain' style sheaths we commonly see from Sumatra.
Another identifying mark is the nature of the kemuning. N. Peninsula kemuning are more 'figured', with more patches of dark colouration on top of the regular golden brown colour. In contrast, Sumatran kemuning are a lot more homogenous, and tend to have wider bands of chatoyance. The first Sumatran keris below seemed to have such dark patching, but that is just an illusion - the sampir has a big crack across the front, and it has absorbed some oil through the crack, resulting in differential colour tones. Another clue is the tighter grains and more obvious white lines in the kumuning for N Peninsula kemuning. I reckon these differences in kemuning is attributable to differences in growing environment. Perhaps those kemuning in N Peninsula are subject to harsher growing conditions, hence, tighter grains (due to slower growth).
Beyond these features, which are readily described, there is also the 'feel' of the work. As I had mentioned before, the "air tangan" (literally "hand water") imparts a subtle sense of aesthetics that differentiates the work of tukang from the 2 regions. This one area can't be taught through words alone. One have to look at and handle numerous examples. And where you do that, you have to be sure that the kerises you're looking at are almost always from that region (e.g. going to Kelantan and Terengganu to look at Kelantanese/Terengganu kerises). Or else, you risk getting the wrong aesthetics ingrained into yourself.
Hope this helps. When I have time, I'd search for pictures of other Terengganu sheaths of this form for comparison.