Re: Nad incoming
The 100 watters sound good because they're fatter than the 50W, but you can reign in the volume by using a 212 cab and putting something with a volume control in the FX loop. It'll act as a global master, so you can bump up the Volume and Gain on the amp.
I'd probably sell the Marshall cab and get a Marshall 1936 cab, and then swap one of it's G75T's out for a V30. Or get an Avatar 212 with V30/H30 combo. Once your head is biased with really good tubes, you'll have all the Marshall tones you'll ever need in that rig.