The ram's from Harbor Freight are pretty cheap. I think I paid less than $100 for my whole set. This system seems pretty simple to me.
There have been quite a few comments on this board about how dangerous it is to compress MB springs without the right compressor. There have been warnings of fatal consequences.

So, give us an assessment of the safety of your system. How strong is that opening link you have at the end of the chain? If you remove the lower control arm. can you completely unload the spring with your system?

It seems to me that you could even make a similar system and substitue a threaded rod with a fat washer at the end of the square tubing for the ram and still have the same effect.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13