Nice find, and they can be used, but these are the later type. They mount on the inside of the door opening which is a bit difficult with the fibreglass being quite thick in this area. These can be found in the UK from breakers too, just ask them for the sets off the rear doors which will have been used less.
The mechanism on the rear of this type is slightly different too so you may have to work out a slightly different way of actuating the levers.
The bolts for holding the bit that goes on the body of the car are also different so if you have already welded the mounting plates into the car, they will need modding or swapping.
The older sets, which even mercedes specialists have extreme difficulty getting hold of, mount on the outside of the door which makes adjustment and fitting much easier. These are the ones lambo use.
I am trying to get a few things laser cut at the moment, and was thinking about getting a plate that would bolt to these to make them mount the same way as the older type.
These are a good find, but just so people realise, you will need to do more work using these and they wont fit in as shown in the build dvd.
This page shows the differences and what type we are looking for. They are for the diablo, but the part is the same for the murci. The black one part way down the page shows the later type which is mounted inside.
http://www.lambolounge.com/Body/Door/latch/door-latch.asp(I modded your post above to include the full url. You can put any web address in by clicking the world with a little chain logo above the smileys then pasting the web address inbetween the two sets of brackets)