Wuff is right ... the number of canes in the circle varied a lot. I have two, one with a CG cane and one without. One has 22 canes in the circle the other 25.
I was told (by Peter Holmes, I think) that all "CT-60 Latticino" from Caithness Glass had Ysart canes at the centre and outside but Caithness canes in the circle.
The design was also made at Paul Ysart's Harland studio and called "Milli Fiori" (see catalogue pages reproduced in Ysart Glass, page 163, with one dated as 1975). Two examples of the Harland version are shown and both have differing canes in the circle, whereas the CG ones have the same cane throughout the circle. If that is a definite regular feature, then it will be a sure way to separate the Ysart / CG ones in the absence of a sig cane.