Wow! That's really lovely, Sue!
You are encroaching into my area of interest here
(But that's OK, 'cos I 'caught' Mdina from you!
)
I would not be 100% sure if it's what would be described as 'rock-crystal' either, as I thought like you that it had to be very thick and complex cutting - but I agree it looks as if it could well be! Would it be worth getting it 'Basil-ed'? I have a nice intaglio cut claret jug which I am meaning to get done some time, but I haven't yet got a round tuit
And Nic gave me the name of another person who repairs glass who he said was very reasonable too. If you want to inquire about the cost let me know and I'll pass their contact details on.