Found this on my first search.....probably other vendors have it too? The "T" or mounting hardware is sold separately. Hope this is what you're looking for?
Mike
http://www.performancecargraphics.com/Dash_Stuff/Hardware/B-body_Hardware.htm DASH FRAME HARDWARE
● Special screws to attach radio bezel to dash frame:
1968-69 uses (3) screws; 1970 uses (4) screws
$1.00 ea. Quantity One: $1.00 Two: $2.00 Three: $3.00 Four: $4.00 Year 1968-1969 1970
● Special screws (4) to attach A/C dummy plates to dash frame
$4.00 a set
● Special hardware for 1968-70 B-body Standard with
optional glove box and driver side plastic upper bezels:
The 1968 and 1969 thick, clear/black/silver woodgrain
bezels are extremely fragile in the area where this
hardware attaches them to the dash frame. A screw
bonded to a tiny plate, with a nut and plastic insert allows
tightening the bezel just snug, without cracking it. One of
these hardware assemblies is used on the driver side
bezel, and one on the glove box bezel. Some 1970
B-body standard black/woodgrain bezels may use
either one or two of these screws.