Ivo - I know nothing at all about the glassworks you are discussing here, but there is something wrong somewhere. Lead crystal, 33% is beautiful stuff to press , and to do most other things. A little slow to set, but that is a problem of production speed not quality.
At Davidsons, although we normally made soda-lime, for one particular order we made a full crystal. Any defects would be down to poor glassmaking or moulds and not the glass itself.
I am, of course, not talking about colours, but am I missing something else in this discussion?