I'm almost of the same opinion. Been at the w123 thing for 10+ yrs now and while some parts and problems are more difficult to resolve, there is always a fix. There are a few parts which create a major problem to resolve, like the NLA heater cores, but even that isn't insurmountable.

As yourself this, how much longer do you intend on running your w123? My goal is another 10 yrs or 100k mi while not breaking the bank on annual maintenance. Also ask yourself, how much are you willing to go without? When sunroofs, door locks, shut off valves, and other non critical items go NLA and die, can you live without their convenience? Hell, most of ours are 35yr old cars that are beat to crap with little salvage value left. I'm gonna upkeep mine til my wife mashes it enough times such that it no longer rolls!