Hi flying free,
well done- corded sounds good, it isn't too obvious but-I would personally put it into the "Paul Ysart made it at Caithness" drawer!
What we know for sure- some apprentices (Peter Holmes f.i.) were trained by PY and shown techniques, so harlequins are supposed the objects for training; but Peter Holmes also said, that he made a snake weight and showed it to PY who took it away (and it's missing since...too good work!). But now: assumption 1- Paul had his millefiori and colour glass locked away and carefully guarded it; so if identifiable PY complex millefiori,latticinio and aventurine is enclosed, it must have come out of the locker in Paul's presence; I'd conclude, the better the canes are, the more the harlequin was produced by Paul himself. Assumption 2- Paul had to fulfill the contract with Jokelson, by supplying PY signed weights exclusively to this US source; Paul had no alternative signature at this time (at Harland he had the H cane)- so is this the reason that there are many unsigned harlequins from this Caithness era? I suppose most unsigned were made by himself!
After 1972 Peter Holmes made PH singed Harlequins at Caithness (Paul had left and founded Harland in ca. 1970)- and the CG cane appeared first ca. 1975/76.
Those pieces had a translucent 3D dark cushion as base, significantly different!-Pauls always had millefiori or latticinio over a thin 2D colour layer.
Finally, Paul was fond of working alone, and assistants weren't shown more than necessary (but we have no evidence for this except eventual unfinished hot weights plunged into a water bucket when someone entered at the wrong time) kind regards, ejm