It should not be that difficult to do oil changes from the cockpit. Worst comes to worse, you install a single line from the cockpit into the sump and add a quart through this line every few hours or so. If there's too much oil, the engine will chuck it overboard automatically - just hope it doesn't get onto the windshield. I would assume though that they will come up with something a little more clever than that.
I'm more curious about changing the spark plugs. I cannot imagine these will last for two months straight. And I also cannot imagine a (safe and practical) method for changing the spark plugs in-flight. (I can imagine a highly impractical and unsafe way, which involved climbing to the highest practical altitude, then shutting down the engine followed by some seriously heroic clambering outside around the cowling to change the plugs, and then starting the engine again at a very low altitude.)
Alternative is a diesel engine of course, although the current crop of these (Thielert) require a gearbox inspection/change every 300 hours or so. Same problem.
Anyway, I don't think this record attempt is going to fly (pun intended). Not because of the technical issues per se, but because of the environment they're trying to do it in.
In the '60, within the military, there must have been a strong "can do" mentality. If you find the commander of your base cooperating, then he can basically order the rest of the base to set aside the regulations, find practical solutions to practical problems, and go ahead. In fact, the commander of the base could actually sell the whole idea to his superiors as research. Both into practical solutions for practical problems, and into the psychology and logistics of running and supporting missions of this duration and complexity. And the results of that research may actually have been truly valuable for the military.
But in todays civil aviation environment there's not a single organization that's involved in this attempt, but a whole ecosystem. I named just a few in my earlier attempt at humor. And all these organizations have a strong "can't do, unless" mentality. And there is no single person in a position of authority to boss them around. So my prediction is that some organization will throw up an insurmountable hurdle to this attempt, "because the regulations say so", "because of liability concerns" or something like that.
Nevertheless, I find the discussion about the practical and legal aspects of such an attempt very fascinating.
