I just got my LC 200 back yesterday after undersealing and I'm very pleased with the result. Anything loose was scrapped off first and then it went for steam cleaning. All bash plates and inner wings were removed to get at the hard to reach places.
Karl, I got a call today. He told the suspension system is replaced, leak fixed and new fluid filled. The AHC is working fine now. He is waiting for parts for fluid and break pipes. Then I asked him to give the car back with under body cleaned and not to apply any black coating to underbody as I want to be very careful about what I do with underbody components and rust prevention
Firstly I'm glad to hear your AHC is all sorted. Steam cleaning is a good idea to make sure anything applied sticks well. The way I look at it is any good 200 series in the UK is worth 25k+ so it is worth preserving. I have pics on my phone so I will try and get them to you.