I actually mentioned during the Chat session last week that one of my many ideas over the years has been to write a TLIAW that would be "What if the two Michael Collinses actually were the same person?"
I'd have it start with just having Michael Collins resign as commander-in-chief of the National Army a few weeks before he dies in OTL, so that he is never assassinated, and that he then within a short time leaves Irish politics. Growing disillusioned with the state of Ireland during the civil war, and still being the targets of assassinations, he eventually emigrates to the US. I would then have the TLIAW in installment upon installment start blending the two Michael Collinses lives together, with less and less of the Irish revolutionary and more and more of the American astronaut, until finally have the last installment have it be more or less entirely the American astronaut.
The absolute final scene would of course be Michael Collins floating around on the dark side of the moon, sipping on the coffee, and reflecting on that he finally, finally, is completely and utterly outside of Dev's grasp.