Gents,
When you study the MO drawings you will find many details that indicate that they were drawn quite early on. Such things as the RFM, gear lever, front brake cable, and particularly on MO19 the two same handed carbs front and rear demonstrate this.
Later they were updated to show Vincent logos, and to add many later additions and changes.
Back to FT80. On a B there is plenty of room to easily fit the rubbers as drawn, and this is the easy correct way. However, the eccentrics of Girdraulics can hit FT80 if fitted as shown. For this reason all C owners endure the struggle of fitting the tank with the rubbers already in place with fat side inboard....or if lucky with how the oil filler limits positioning by putting the rubbers in later.
Strapping the control cables to the ufm means you only need three and a half hands to do the job.
Regards
Tatty