I would say yes, the B-125 and the B-135 are laminated. Here are the full descriptions...
All Gibson Basses are full three-quarter size B-125 BASS $125.00
Here is the Crackproof Gibson Bass especially arched to produce a powerful, well balanced tone. Spruce top; maple back, rim and neck; ebony fingerboard and tailpiece; flake grain bridge; individual machine heads; solid end pin; adjustable $1.00 extra; finished in rich antique brown.
Same as B-125 but made of woods especially selected for their beauty and texture to be enriched by the Gibson natural finish.
The top isprecision carved from solid blocks of fine grained spruce, choice curly maple back, rims and neck. Finest ebony fingerboard and tail piece; selected flake grain bridge carefully shaped and finished by hand, individually replaceable machine heads; rosewood adjustable end pin; rich amber brown finish.
Same as B-250 but made of woods especially selected for their beauty and texture to be enriched by the new Gibson natural finish.