Given there are two pace stickers on the cowling and several cowling bolts missing I'm going with a cowling swap for now.
Agreed; I reckon that's the most likely scenario.
Wonder if that means the impulse starter got swapped too?
Could well be, but it isn't possible to say, as they're identical on those two models - P/No 12-236. They both have the chrome dress trim, too.
It should have a second pair of 'lifter' blades fitted to the top side of the blade disc, too.
THESE ones.