Originally Posted by
SchmutzigMSP
Let's just say I know that I should make the connection in time since I would be connecting back to the same aircraft I arrived on.

I've done a MR to LHR returning on the same a/c without any problems, but the turnaround time was more like 2.5 hours. I ended up cooling my heels in the lounge for a while though, so you should be ok if you're quick on your feet.