Hello, I am hoping I can get some advise on what part I would need to fix the following problem

I am giving my sisters focus (1.8 petrol, manual, 2000 reg) a good service, oil filters etc... and I noticed that she had a leak from the end of her gearbox (or possibly diff, am unsure)

Now she did say it has had a slight oil leak for a couple of months, and said her boyfriend though it was the sump, so it took me a while looking to find this, and only found it after taking the car out for a run to get it nice an hot (thinking that it would drip easier if the fluids were warm.) but it seems that the end of her gearbox\diff has had a knock from somewhere and bent, meaning the gasket isn't sealing it properly and also meaning her and her boyfriend can't tell the difference from golden to brown coloured stuff and red\pink.

Anyway my description prob isn't helping too much, and they say a picture is worth a thousand words so here it is:

The picture is taken from behind the passenger side front wheel.

I just need to know what that end plate is, where to get it, and how much it will be, I can do all the work myself as am quite good with a spanner, but need to get it done reasonably quickly as I need to sort out my cars inlet manifold gasket and replace my radiator this week as well and will be away for a while after that.

I only had my mk1 focus in the garage yesterday to get the seals on the gearbox replaced. I had noticed a leak in the same area as yourself. The garage done the work but they informed me my power steering pump was also leaking. The have greatly reduced the trickle of fluid that was leaking, and it's only a fine mist now. It might be worth checking if it's the pump.

It's the gearbox end plate. Simple to change, whtch out for plenty of gearbox oil! If you jack just the passenger side up you'll reduce the amount of oil that will come out.

thanks for your reply, have the car up on axle stands in the garage right now, had a hell of a job trying to get that lower bolt off (you can see the edge is bent up) and will be popping down the local dealers to get a replacement tomorrow, if they don't have any, I will get a gasket and try and bend the plate back, though may have to get my vice out to do that as it isn't exactly thin metal.