Hi Paul
Well I could be wrong not having it to look at in real life

But to me it looks like clear over red and yes, it has what I think of as a beautiful effect. I prefer those engraved clear over colour rather than colour to clear. The engraving is really good and I think quite deep but the effect is subtle and sophisticated (imo), precisely because it's not 'showing up' as clear out of red surround. I don't see that many of these (clear over colour engraved) because I guess the colour over clear showed off the engraved design better. The ones I think I notice/recall seem to have been amber but I'd need to have a good look around this weekend to see if I can find examples/references.
Covering all bases here and excusing myself for being wrong before it turns out I am

, it could also be that the red of the back wall of the goblet is making it appear red and it may well be colour over clear. But it doesn't look like it to me from the photos.
I also think the central lens at the back might have been where some initials may have been engraved for example. So a celebration type goblet. This one is plain lenses though so possibly never purchased from the maker perhaps? Or maybe they buyer just decided no extra engraving, perhaps it was just purchased because it's quite big and beautifully engraved and a lovely thing.
If it were mine I would be starting to look 1840s/1850s and work from there. I could be many years out of course but that's where my instinct would tell me to start looking - because it's clear over colour, the red, the foot, the way the merese on the stem is cut.