Josh wrote:
I've signed a contract with Home Depot for them to install a new
Quartz countertop to replace the nearly 50-year old formica one I now
have. I think the sales lady at HD told me if I removed the old sink
& countertop myself I wouldn't have to pay an extra removal/disposal
charge.

I have an L shaped countertop. Was it customary in the late 50s to
simply nail the plywood top down to the cabinet, or would they have
used an adhesive.....or both?

Anyway, I would welcome suggestions as to how to get the top loose.
My guess would be upward strokes at the overhangs with a hammer,
followed by a pry bar. But if anyone has a better idea, please share.

If it was a post formed top or pre-made one installed over the cabinets then
it would be screwed through the top rail of the cabinets into the bottom of
the countertop. If it was made in place, then anything could be used. I
would doubt that glue was used but who knows. First thing I would check is
for screws from below or evidence of any glue squeeze-out. If there is no
obvious signs of it being attached from below, I would use a heat gun to try
to peel up the laminate and look for fasteners under the laminate. Hammers,
pry bars, etc. could cause a lot of damage to the cabinets so go slow and
carefull.