I believe there is a difference in the manufacturing process - between milk glass and opaline - the former will appear opaque, and the latter has a real translucence and should show a fiery glow when viewing transmitted light.
Could be wrong but as far as I know opaline is not cased in clear. In the past we have spilled much ink on discussions regarding opaline - you may find it of some use, and interesting, to read these conversations - if you punch the word opaline into the Board's search (at the top) you will have enough to read for the rest of the week.
The condition of the gilding appears exceptionally good - it may be that these are more modern vases from Czechoslovakia, where pieces with gold coloured decoration - similar to these - were produced commonly in the 1960 - 70 period. Are you able to tell us where you acquired these pieces, and may we see a picture of the underside of the foot, if possible, please.
