I will be offering this service for people in the states. I have fixed/downgraded over 350 ps3s so i do know what i am doing. I do offer the service for a cost. Pm and i will give you a link to a site to where you can see my work. If this is ok with the mods here i could post the link. I am a mod at another site and there is a ton of feedback for me. If it is not ok with the mods about posting this please let me know and i will take it down.I could post some of the pictures here as well.
What you do get when i do a downgrade is i clean the ps3 and replace the paste on the heat sinks above and below them.
I also do all repairs on ps3s, xbox360s and wiis. I can do anything that has to do with soldering.
Here are some pictures.
Here is a video of a dual boot ps3 i did with the e3 linker and the e3 install. thanks