I have a Unghans B26 279 Westminster chime in a grandmother cock. The time mainspring has always been difficult to wind. It seems to be too stiff. The clock would run fast and about mid week run correctly and by friday run slow. I removed the barrels and springs, the springs are new. The time spring is much shorter and stiffer than the strike. I ordered and replace the time spring matching that of the strike spring. Now, it does not have enough power to run. Any idea to the correct size for this clock?