I've managed to snag a few replacement glass sections for the Smok Big Baby Beast which allows for the use of the Baby Beast RBA deck. This glass is the same diameter as the stock Big Baby Beast glass at 24.5mm but is 3mm taller.
Here is the stock glass in red with the RBA glass in clear:
Available here:
http://vapeguy.co.za/accessories/spares-parts/smok-big-baby-beast-rba-replacement-glass-tank
Here is the stock glass in red with the RBA glass in clear:

Available here:
http://vapeguy.co.za/accessories/spares-parts/smok-big-baby-beast-rba-replacement-glass-tank