I'd be interested in Johns output between the J glass and St Kilda era and the early/mid 1990's.
I have a Ysart style butterfly set up with two distinct coloured millefiori canes to form the upper and lower wings. Dated 1992.
Everything else that could be earlier looks to be just JD or no signature cane.
I've certainly never seen anything labelled Crieff Glass, or identified anything definitely produced on an ad hoc basis from 1985 to 1992.
I feel a trip to Crieff is needed!!!