yes, they did use "winter fronts" commonly in the day!
if your thermostat is in right and works at the temp called for [185] the engine HAS to get that hot before it opens and circulates water outta the engine and thru the rad - if the stat doesn't open the engine heat should continue to climb til the ol girl blows up - where are you reading the 165? have you actually tested the thermostat in a pan of water on the stove, w/ yer wife's good candy or meat thermometer?
Bill