Rebbi, I have huge hands. I can, with appropriate care, manage to rotate the volume knob without toasting my fingers.
I would encourage you to think about the tube rolling in this way. The stock tube that is probably just unacceptable is the rectifier. You can get a superb new production cryo'ed 5ar4 Gold Lion for about $40. Just figure that into the price of the amp. The dynamo sounded fine with the stock rectifier, but they tend to be short lived. Mine started arcing with about 10 hours. With respect to the rest of the tubes, I don't know of any amp that sounds best with its stock tubes. That is why Charles sprung 2K for his 300Bs.
As for only having one input, if that doesn't work for you, that is probably reason to move on to another option.
With all due respect, I think you are suffering from analysis paralysis. Why not try the Decware, since it has a trial period? If you don't like it, send it back and try the dynamo. I suspect you will be happy with either, but the fundamental question with either amp is will they be better than your Manley? That requires an A/B in your system, hence the good advice from Charles. It is time for you to listen.