Hp67 and others, Drill or not to drill?

[Raymond Del Tondo]

From the pic you provide the back plate already has ears at two edges.
That's not what I would call "pristine";-)
Maybe the ears are there because someone tried to peel the plate off.
There are several possible reasons why the edges are not as flat as the rest.

AFAIK it is possible to remove the plate without much damage, but I don't exactly recall the procedure.
The right amount of hot air, and much patience will help.

I repaired many HP card readers in the past.
On the HP-65/67 , I always push very small holes at the middle of the two screws hidden behind the plate.
Using a small Phillips screwdriver will avoid widening the holes too much.
Unscrew the screws only as much as needed, so their heads will stay under the plate.

Of course all my customers knew beforehand that the plate would be pierced.

This method may not be suitable for the perfectionists, but trying to remove the plate undamaged is much more effort,
with no guarantee of success. If it fails, you may have to provide an aftermarket plate.