I did some research on the SB-2T and found that 30th Anniversary SB-2 was built with a tone control and side jack. These were available from 2010-2012.
In 2013, G&L dealer Rocket Music commissioned G&L Sales to do a special run of the SB-2 with tone control and side jack, same as the 30th Anniversary SB-2T.
Today, I saw four SB-2T basses listed on the G&L Inventory list (sent to all G&L dealers) and are available to any G&L dealer for sale. See:
G&L USA Factory Inventory.
I am checking with one of my contacts at G&L to find out if this is a new standard model or if they are still Special Builds.
Hope this helps.