Done some investigation today. (can anyone tell what box I have by my photos? All I can see is a leyland logo on it)
1) It's running duration dependent, not temperature. I warmed her up and she leaked.. I worked on the floor pan (removing the ally that covers the trans tunnel for a good hour. Started her up and she leaked immediately - with cool oil. Car on stands, in neutral. Later tried again (with floor trans tunnel cover removed and I could see the leaking straight away (as per linked video). When running in neutral I assume the spinning gears are whipping the oil around and finding the leak point.
2) The leak is coming from some area that seems to be near the gear selector. From under the car it leaks near a join (but not from it) under the gear stick area. When looking up I can see the the oil is not coming from any visible location - it is coming from above where I can see - so presumable the top or upper side of the area in question).
3) this is a very recent phenomenon. The only things that have changed are:
a)I've moved and now park on a moderate incline (bonnet up)
b) I've had the car front on axle stands for a week whilst I've worked on the crank pulley. So it's been at a steep angle for a week
c) I've gently hit a speed bump at low speed. No marks on the gear box. Loads of scrapes on the sump. No engine oil leaks.
I'm wondering - perhaps when it was on stands pointing steeply upwards for a week, maybe gear oil has got somewhere it doesn't usually go at the back end of the box and now it's all getting flung out somehow? (I've never topped it up)? Clutching at straws really.
Photos and a video below.
Looking up from underneath:
And a video:
