I've fixed similar myself. On plus side, the main dent in the door is large with no sharp creases, so could be more easily worked out if you can get a dolly on the inside. More concerning is the hard hit at the corner of the door and quarter panel. If the "pinch-weld" is pushed in, many say the door can't be salvaged. But your corners may not have moved. Plus side is doors can be replaced, if needed, and you are in the heart of W123 sales, though even in SoCal salvage yards they are getting rare.

The quarter panel can be fixed by pulling and filler. I have the Harbor Freight Stud-welder, which I've used on several cars. It works best on my newer cars with thinner sheet metal (1996, 2002). My 1965 Chrysler is hard to pull since thick metal. My M-B is in-between. In older days, they screwed into the sheet-metal many places to pull, leaving holes with filler squished thru. Don't fear filler since show cars skim all the panels of the car with filler to sand perfectly smooth. After beating as close as possible (but not too high, don't over-pull), start with fiber-glass filled filler (ex. Bondo Glass). I have even used woven fiberglass and epoxy over large areas or holes. Even once you think you are close, plan on at least 5 passes with filler. Those curves on the quarter panel will take repeated fussing and sanding to match. I only get a few swipes with filler before it starts reacting, even in cold weather. Don't believe the "5 minutes" or such.

Painting will be trickier. If you can take a part in, say your fuel filler door, a paint shop can match it with an optical sensor. You could also give them the paint code, though yours may have faded with time. Will probably have to paint the door up to the trim so it looks uniform, since hard to blend with clear-coat.

Re cost, their insurance will pay per a body shop estimate, which likely may be "totaled". You can take the money and do nothing, have the shop do it, or do yourself. I always pick the later. Won't be the first time an idiot runs into your car. 75% who've hit me have been uninsured.

__________________
1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans