Mismost--
That was the point I was trying to make. The w123 is the cockroach of the Mercedes-Benz line. This likely won't change, even in 20 more years whenever cars of the late 70's and middle 80's are actually rare sights on the roads.
My recommendation would be to put the car together as cheaply(but well) as possible, drive the snot out of it and hope everyone else's gets wrecked so it is actually a notable car and not just one of a couple hundred thousand that are still on the road
Find a finnie, find a ponton... work on those in a restoration. Just repair the w123 and enjoy it. Save its full restoration for 2025, it'll be worth it then.