Hiya Jo, whilst I would have agreed with you about only jetons being used on French roulette tables and the clay style on AR tables, I have been told that jetons were also used on the BJ tables at the CHC in the 1960s and if you watch the clip from "A hard day's night" there is a roulette table that uses a rake but the chips are obviously chips and not jetons but overall, yes jetons were used on mainly French roulette tables (and baccarat tables too).

"The man who haunted himself" (also filmed inside Le Cercle) shows jetons and plaques on the French roulette table.

As to why French roulette was phased out it essentially came down to profits not to make it easier for dealers, although that may have also been a factor, as for the cost (and floor space) of running a French roulette an AR table made much more money (more spins, less staff etc).
Personally I can see the 3 chips that were on ebay as London French roulette jetons as they definitely had at least 1 until the early 1970s when they were totally replaced by AR tables. They also had cash jetons so that would tally with having a colour jeton on the table I'd say.
Funnily enough there are no known Portsmouth cash jetons although maybe the lunette one had a value on the other side. As it came from a BetG brochure and only one side is shown, it's possible. I know that the London ones had the value on both sides but according to somebody that knows a lady that worked there, they say that there was only ever 1 French roulette table at Portsmouth which I am inclined to believe as it was a small casino and I doubt that it would have been able to accommodate more than 1. Tibs was a much larger casino and they only had 2 French roulette tables but they were closed in the mid 70s. I am still asking around to see if anybody has any more details that may clear up the mystery without us having to speculate or just make things up for the sake of it.
I am also in the process of getting photos of AR chips definitely used at Portsmouth so hopefully there will be ones that have different inserts which (in my opinion) denote different tables so we may be able to work out how many AR tables there were although, obviously, over time it may have changed as Le Cercle (and others) did.
The racetrack on AR tables is a relatively recent addition as we used tier, voisin and orphans buttons too when I worked in the provinces along with neighbour buttons that went on the wheel. In London we usually placed the "French bets" as they were called if no buttona available.

Hope life treats you well.