Hey Allan,
Check the HCE roulette on my website and click on the name. It will link you to a pic of a postcard taken early in Caesars of a roulette table and it shows 'generic' roulettes being used. The other chips look 'legit' so these may have been first.
I do not believe the HCE's were roulettes since only TWO styles are known, no letter or number on the chips either. I'm sure Caesars opened with more than ONE roulette table!!!!

Steve