I'm afraid I'd have to disagree, Keith. The two marked Mdina, the tall bark effect vase and the smaller bottle, have colour that comes from being melted in the pot, while your PW is surface decorated with enamels which as added to the gather of clear glass, although the streaks you refer to are similar on all three pieces, these come from silver salts, which colour glass, and sometimes, the salts turn to gas in the heat and give iridesence when the glass escapes from the moil during production. I'd say your PW is considerably later than the other pieces, if it is Mdina at all. The base looks completely wrong to me, I'm afraid.