Helmet storage on Vespa Primavera 125...

Ive just got my first Scooter , Vespa Primavera 125 (2015 )

 I found that my crash helmet a Medium sized  full face Evo LS2 , won't fit  in the under seat storage . (The helmet is measuring at about 26cm with circumference  of 88cm)

  Its just marginally too big to see the seat close properly and latch shut .  On that occasion I took the helmet  with me in a holdall. 

"Visor Down website  2014 review suggested  in [i]A button above the glove box raises the seat to reveal space for even a generously proportioned full-face helmet. "[/i]  

 

Does this suggest Ive landed myself with a helmet (bought a day before I got the scooter .. thats above standard size.(  I might get away without locking it in some trips as it looks shut but I wouldn't want to risk it. I guess Im looking at  getting an Open Face helmet which look to be a bit smaller . Id welcome any suggestions on this and have any other Primavera owners had this issues ? 

Richnsoul UK