Sure it is! I checked this up in the manual where it explicitly says
that masked ROMs (8041A) can be read with the same verification
procedure as the EPROMs (without applying programming voltage, though).
I probably was applying modern mindset to the question by assuming that
back in the 1970s people were obssessed with protecting code from
cloning as they are now...
Unfortunately for me, this makes little difference as I have no chip to
dump... :)
Bye,
-- F.Ulivi