I’m of the age that even though I haven’t seen mine in a good while, it’s not been used much of late but I remember the knob not being stiff although it did not work properly……..I’m off to the garage now to give it a pull.
The heaters on all my Morgans never worked well and I relied on the engine heat in winter but not fun in the summer .
Hopefully things have improved over the years ???
MM
PS Delete if too childish although would be interested to know if heaters now function well in new Morgans…..