Scart socket that doesn't take the plug?

I have a oldish TV that is being pressed into use by my son for a old
playstation. The playstation has 3 leads that plug into an adapter to
make it a standard scart plug.

The back of the TV has a antenna connection and what appeared to be a
scart socket. However after trying the usual brute force and
ignorance approach I found out that the reason the scart plug wouldn't
go in the socket is that although the tv scart socket is the correct
size, at one point on the perimeter it has a small labyrinth shape
mouded in, so that a standard scart plug won't fit it. Scart is
rectangular, with one side made a bit pointy. This labyrinth is on
the opposite end to the pointy bit, the short (straight) side.

My first thought was that the manufacturers had made a special so that
you had to plug their proprietry lead in, but then I wondered if there
was something more to it. I could make a scart plug to fit,
mecahnically into the socket by trimming the metal skirt away at one
place, but is there something likely to go bang in the TV or
Playstation if I do so.

Iny ideas?

Thanks,
Eric