It is, just like a window blind. There are 2 tabs on the radiator mount for the roller, the cable came off the middle of the bottom and went out forward under the radiator, there is a ring on the end of the cable that hooks onto a small hook on the frame to hold it down. Took mine off when it seized up a couple of decades ago so can't take pics of the installation.It is a shutter kinda of like a pull down shade that goes in front of your radiator to block the air so it will warm your engine faster in colder climates, for the heaters and such! I believe it was an option on some? When warmed up then you raise the shutter.
What good does a higher temp thermostat do if it doesn't get warm enough to open the thermostat in the first place? I'm refering to a 3B engine and at -30C (-22F) the 188degree thermostat doesn't even open, why would a higher temp thermostat open? The B engines have a bypass system in the termostat housing so coolant circulates through the engine and heater core but not the radiator when the thermostat is closed. You can't even get any warm air out of the heater unless you're doing something like 100kph (60mph), so at those kind of temperatures in city driving you probably could do without the radiator at all.Ditto an/or goto a higher temp thermostat
Whoeever said that?
If you we climbing a big hill in a blizzard in Antarctica I'd still expect the thermostat to open .... eventually.