I think my thermostat was sticking - yesterday the temp went very high, and then suddenly dropped back down to half way. I imagine if it's sticking closed it would also be pretty sticky open as well.
Fitted a new stat, and certainly getting a lot more warmth out of her.
Another “lack of regular use” symptom that will not recur now you have changed the thermostat and started to use the car regularly. This phase does not last long. Our 1985 4/4 had different issues when we first got it in 2003. Less than a year into ownership and all was sorted.
