Roy, I have a Grand Jubile (as spelled on the top tube) and recently had a Jubile Sport. The GJ is std vintage (early-70's) with nervex lugs, Stronglight, Huret, 531 tre tubi, etc. The JS (early-mid-80's) was columbus inexternal (internally lugged), Nervar, SunTour. Its my understanding that the GJ devolved into the JS but your GJ could have been either an interim model or a short-lived proper model (probably two ways of saying the same thing). What is the componentry of your Inexternal GJ?
Of interest to other motobecanephiles, while next up the model ladder from Grand Jubiles, I find the Grand Record not as interesting in spite of its full-531. It usually came with Campy Rec (yawn) while GJubile came with delicious french components. Thus one of my projects is to fit a GR same as GJ (frame geometry is nearly identical) and have best of both worlds, french and frenchyer.
Jack Romans
Sacramento, Cal