Crankshaft / transmission on used S

[Rosino]

Hi,

I'm interested in a 2003 Boxster with 25k miles I have found here in London.

The car seems to be in brilliant conditions but the service history shows a couple of things that leave me puzzled.

The last service costed a whopping 2800 pounds (5600 USD)... and the owner couldn't explain exactly what was done on the vehicle. I have photocopies of the invoice and it states amonst other things :

-R+R CRANKSHAFT SEAL RING AT FLYWHEEL END (£154)
-R+R TRANSMISSION (£429)

Somewhere else it says
- REPLACE INTERMEDIATE SHAFT SEAL (£143)

Can anyone make out what these things actually mean ?

Thanks for the help..

Richard