If it's any consolation, I've seen a couple similar cases here in Halifax, supposedly immaculate 240s with very low mileage, just driven back & forth to the grocery store & to church. The problem is that such a life is murder on a red block (and worse with white blocks, I've heard). One of those cars was, I'm sure, never fully warmed up nor went over 2500rpm in its first 15 years of short drives around town. The proud buyer got less than 10,000km out of the motor before it died. Once he started using it like a normal driver would, it went to pieces - knocking, smoking, valves sticking. And just about every seal on the car started leaking. A high-mileage car can be substantially less problematic sometimes. Having said that, if I found a 240 with only 26k, I'd buy it in a heartbeat and take my chances on needing to put a motor in it. I wonder if a good dose of Seafoam & AutoRX would adequately clean things up, without causing more harm by breaking up sludge/carbon and plugging the oil passages with it...
FWIW, I heard that one low mileage 240 Classic sold here for $12k. Smokes like a diesel on startup, too.

-Chris