This page describes four Gibson flat top acoustics, the J40, J45, J50 and J55 - though the J50 is not pictured.
UK prices (1981) were as follow: J40, £789; J45, J50 and J55, £829.
$4250
$9000
$1500
$6594
$4995
$3000
$1800
$600
$1995
$649
$2999
$4999
$195
$4000
$2499
$2800
$8899
$1520
$4395
$3480