I like the laced up theory
I'll have to carefully power it up and see if it keeps the tape out, so
its
only the clutch I'm not sure about, any clues.

You can usually feel physically if there are any clutch issues. If the two
halves of the clutch turn with respect to one another, very easily, then the
clutch needs replacing. A big clue here is that the wind / rewind operations
will usually be a lot poorer when the driven spool has a lot of tape on it.
If you stop the operation towards the end of a cycle, and then try to
restart it, often it won't be able to get going again. However, this symptom
can be exacerbated by the friction problem that I mentioned, in combination
with a slightly below par clutch, which would otherwise work ok.

The worn head drum friction problem really is quite common on machines that
remain laced up, and have done a few year's service. If you try to observe
the operation of the machine with the cover off, you may have to hold your
hand over the centre of the deck to shield the optical tape-end sensor from
overhead light.

Arfa