I got interested in Arcopal because I heard it referred to as French Pyrex. And while it’s pretty similar to vintage Pyrex — milk glass, oven safe, cute patterns, etc. — the only real connection is that the manufacturer, Arc International, was licensed to sell Pyrex in Europe for a time. Arcopal is a separate brand introduced by the company in 1958.
I haven’t been able to find any pattern references for Arcopal, but most people seem to call this design French Hen. I got this casserole dish from Goodwill’s online auction site, which is full of temptations for the impatient thrifter. Word to the wise: Beware of shipping charges when shopping there (or on eBay for that matter), as they can be exorbitant.