The rear subframe needs a good look over and you need at a minimum new bushes and bolts for the subframe, and swaybar links (use w124 wagon ones, they are metal)
rear SLS parts need replacing, even the accumulators and strut hoses look tired. Rusty banjo bolt is not a good thing, but hopefully just surface rust.
noticed a bit of rust under the urethane near bungs/grommets. attention required in these areas (the rust hides under the deadener and can bring nasty surprises hope yours is ok)
rear springs look like they could do with cleaning and coating.
radiator support (lower) needs attention.
master cyl reservoir looks nasty.
Do yourself a favour and replace all the coolant line hoses when you have budget. (in particular the heater hoses through the firewall and the monovalve)
strut tops look like they have been replaced and no cracks.
just needs a serious gerni underneath to reveal all the crap and a proper spray down with clear body preservation wax.
Some bits and pieces to be re-plated, but all in all it looks like you have a pretty solid setup.
I reckon a rear subframe assembly overhaul is in your future and suspension bushes in the front. (LCA, swaybar)
There is staining on the driveshafts, and some rust, I'm almost guaranteeing the wheel carrier bearings are shot and the bushes look tired, but gerni it all down really thoroughly and have a second look underneath after it has been properly cleaned, so you can really see what you are dealing with.
You may be pleasantly surprised how good everything actually is.
but yes, a major undercarriage clean and lube/re-seal(wax) is a definite first step to making it last.
FCP Euro have a special on lemforder bits at the moment
1987 201.034 - € spec 5sp. Blauschwarz- Hermann.
1992 124.051 - 6sp man. Iceblau - Gretel
1992 124.090 - 4sp auto Malachit Grün - Beatrix
1987 107.048 - 4sp auto Signalrot - Stella
2012 212.074 - 7sp mct-speedshift Diamantweiß - Klaus
numerous other non-MB's
MB exit lounge: 1989 201.035, 1987 201.029, 1987 126.039, 1972 107.023