The RGF BB shells were widely used and found on many different makes, from Pugs to Holdsworths to Allegros. Here's an exchange from the CR list archives, including a bit from Sheldon:
It's a pressed steel BB, made by GARGETTE FRERES, the "R" he thinks
stands
#>for "Racord" (spelling, word?) which could be "bottom bracket " in
French.
#>Can anyone verify? Monsieur Sheldon?
#>
#>"Raccord", (m.) is the French word for "lug", and also is used for a
pump
#>head.