Questions about the SR-71

I got a rather interesting message from Sean (SOC) regarding the Blackbird with the M-21 drone on it.

In the message he tells me that the D-21 was only launched from the B-52 whereas the M-21 was launched at a higher speed off the sled.

So what I want to know is which Sled was the lauch platform for these drones?

Also I’d like to know if the performance of the SR-71B (Twin cockpit, pilot trainer with the raised second cockpit) was different due to the second cockpit being raised.