Hello Schrock,
These are bargains by today's standards for a Mercedes convertible (way over 100,000 made). They are gas guzzlers except for the 6cyl euro delivery version (280-SL W107). The earliest USA versions and the euro delivery cars had the pretty small chrome bumpers. The USA cars had the big ugly black rubber safety bumpers. a nice combination is an european model with the small chrome bumpers, high compression engine, euro headlights, and factory front spoiler.
If maintained these are very drivable, modern and reliable. 1975 thru 1980 USA delivery cars are the worst years. Manufacturers were having to add lots of USA emmissions equipment. The catalytic converter, lower compression and other emissions droped the horse power on USA models to 185hp! 380-SL, SLC had timing chain problems. They do handle a little heavy but the V8 engine is impressive and durable. Poorly maintained or high mileage examples may be ready for an expensive valve job. The bottom ends are normally indestructable. thew 450-SLC 5.0 is the rarest and most collectable. They had the 5.0 liter aluminum engine around 900 were made. Only the coupes (SLC) were produced.
Things to look out for; chasis rust, cracked expensive exhaust manifolds, inoperative climate control or heating system, worn electric window regulators, oil smoke (valve job time).
The later 500 and 560 series are more powerful, refined and luxurious as stated and a bit more expensive. Gas consumption can be an issue. 18mpg on the road and 13mpg around town is not unusual for an USA emission W107.
Joe Alexander
Blacklick, Ohio
1974 450-SLC all euro specs with 4spd trans.