I went with Wardair on the 727 in 1967, Gatwick-Sondrestrom-Vancouver, and subsequently nonstop on their 707 in 1969 and 1971. At that early stage in their development they used an "affinity group" organisation in the UK called "Western Canada Alliance", which was run I recall by a husband & wife couple called Overton. Goodness, that recollection has been up in my brain for 45 years without being recalled until now. It was notable that in Vancouver Wardair had a downtown streetfront office in the late 1960s right alongside CP Air and Western, staffed by someone in FA uniform, whose principal job seemed to be to receive phone calls from those who wanted to fly to Britain and direct them to the relevant affinity organisation who had chartered them on that date.
The Wardair 727 sometimes laid over at Gatwick for a day or so between charters, and I read one account of it being subchartered to cover an IT flight from Gatwick to Corfu and back due to some problem at the original carrier !
Back to the original question but by around 1980 CP Air were also operating a substantial charter operation to Europe which actually appeared in a 4-page insert in their mainstream timetable, showing just days of operation. This showed they ran from Toronto and Vancouver to various UK points, and also to European points not on CP schedules like Frankfurt and Brussels, some routes like Gatwick several times a week, with both DC8s and 747s (the latter shown in bold type). They evidently had several aircraft fully employed on this work. Canadian charter-configuration operators have all long had an opposite peaking to those from the UK, peak season is winter, from the likes of Toronto down to Florida, the Caribbean, Mexico, etc. Wardair and the others followed this pattern as well, deploying across the Atlantic only in summer, although Wardair started to creep to an all year operation.
I think the 1971 return Wardair 707 was where we left Vancouver and flew overnight to Gatwick, to find the CP DC8-63 and Pacific Western 707 there which we had seen departing Vancouver.