returning to the original post for a moment, there is some small, but possible nudge in the direction that, as suggested, this piece may possibly have a genuine Harrach provenance.
In their 'History of Glass' by Dan Klein and Ward Lloyd - page 174 - the authors show a Sugar-Water set in uranium glass, which they attribute to Harrach. c.1840. Although in the book the colour is not qualified as honey amber, it certainly looks to be the same as this piece, and the glass tray on which the decanters etc. sit has a rim cut in very similar wavy fashion. Not remotely conclusive, of course, but if nothing else seems to lend weight to the likelihood of a possible Harrach origin. I don't know how distant, geographically, Harrach and Riedel were from each other, although in the 1840's they would, of course, have both been Bohemian (one is now Czech. and the other Austrian) - but obviously near enough for the grape vine to spread the word.
I assume a 'chigger mark' is a flea bite of some description - yes/no? ...............and since I know very little about preserve containers, can someone tell me the origin of describing this open topped, 'sugar' style item as a 'marmalade'. Is this an Americanism
Anyway, congratulations Dave - gorgeous piece.