Works for me.British companies were sometimes licensing French and German engines, so licensing US engine might not be such a stretch.
I do like the "off-brand" feeling from it, so I'd be inclined to use it.The R-2180A (pre-war engine) is a really misteroius engine - yes, we know the 'hard' data (bore, stroke, HP, rpm) but the 'soft' data is as good as not available, like the reliability. Just by looking at cubic capacity and power, it might be a good choice.
I'm happy to leave the displacement alone, then, & I've been presupposing "best practise" on carb type selection. My thinking is, tho, none of the a/c engine makers seemed to use enough carbs, & that's an obvious chokepoint for power. The other option is reducing friction, which implies early discovery/development of *Teflon, which seems less likely.The Buzzard was already a big enough engine, 36.7L, so the dispalcement can remain as-is. RR have had good superchargers even before Hooker arrived, obviously Hooker will improve it still. Carb - use the 'injection carbs', not the 'float carbs'.