Hi All,
Anyone had experience with leaking aircon compressors?  This is the second one (second hand) I've put in and it is also leaknig. What are the chances of getting a new one from Toyota?
I know this is pretty old now, so is there an alternate model which will fit on at all?
Thanks for your help in advance.
Tom.

Did you get it serviced before it went in?

Service??  I didn't know you can get them serviced.  
Do you know who can service them?

any aircon joint should be able to do it.
 
I got mine reoiled before it went back in. Can get the rubbers done too I'm pretty sure but they told me I didn't need to.

Probably best to define where the leak is from.
To correctly service mr2 air conditioning if not fully serviced during your ownership...
degas, replace all orings in all joints ($30 or so from repco etc), remove evaloporator (wash with non purfumed / plain dishwashing soap and warm water), replace the tx valve ($100), dehumidifier($35), change oil / seals on compressor (old school air conditioning shop), reinstall compressor and add gas. You can cheat the above list however at this age likely to fault or not work as well.

Thanks for your help guys.  The original air con system was removed due to a head-on accident and was never re-installed.  The car was then put under covers for over 15 years until late 2017.  Now registered again and can be driven on the road, it is much nicer to have air con.  So I asked my mechanic to acquire all the necessary parts and re-intalled the air con into the car.  
Anyway, sounds like there is hope. I will get it fixed eventually.
Thanks again.

Get the system degassed - not good to breathe in if leaking.

Doing the above is actually very easy, time consuming so do a little each weekend, online guides, need basic spanners to do the work, parts available at local auto store.