Not positive, but I do not believe Jeanneau's use "JEN" back then for the ID number, at least my 85 Arcadia does not start with "JEN" it has an "IRIAR" start to it. The more recent ones may very well have a "JEN" as the first letters in Hull#.
But as noted, this appears to be a Cal, the 8 may very well be a "B" but appeared to be an 8.......
She drives me boat,
I drives me dinghy!