I just tried that circuit from DC on the MT7201, could see some dimming, but i'd only say 75%-100%. I tried a few different resistors on the base but still the same. I tried it connected to the arduino and running the 'Fade' sketch from the basic examples.
I keep thinking the ADJ pins are connected to something, I could measure about 0.5M ohm between it and some of the others so I tried lifting it, but managed to snap this one too. No ADJ pins to play with anymore, but I have some more bulbs on order