There's plenty of motors out there that have been "upgraded" shall we say with the hydrofan props.
C.266. was no different in this respect.
I very strongly beleive that the original prop for these would have been the SD swept back style. My AC3392 and AD1584 both have these and were fitted when i bought them. It doesn't really mean anything at this stage i know, but it just looks RIGHT to me with the straight out back pumphousing, the same as you'd expect with any of the wartime motors. And seeing as this motor was likely to have been manufactured in a time of hardship right after the wars end, it makes even more sense to me that a small company such as BS were in those days that they would need to draw on wartime reserves. There was nothing else around to fit except wartime stocks.(whatever they might have been)
Later AD's and AC's (with slotted core plugs) tend to have the "bowtie" prop unless they too have been "upgraded" at some point. (different pumphousing on them)
I can see why these props get swapped though. Once they get too badly dinged and bashed up it becomes a pointless exercise to try and repair something that's already been repaired several times before.
So, (maybe) after a quick look through the parts list/catalogue of the time, an owner might well be tempted to fit the current model of prop to their own motor seeing as it's a fairly cost effective way of improving the performance (albeit slightly) of their outboard.
Hence why nearly 60 odd years later we see loads of hydrofan props fitted to 102's. Doesn't mean it's right, doesn't mean it's wrong either, it's just the way things are sometimes.
But you just KNOW when something looks right, and to me the SD prop looks right on a nippled gearbox with the straight out back pumphousing.
There are however the odd photograph or two (on the main site) that shows some motors fitted with a "bowtie" prop on a wartime spec gearbox just to add even more confusion into the mix. I tend to ignore these for now and concentrate on what the data sometimes tells me. Sometimes i'm lucky in that a motor comes across as "original" or mostly original bar the odd swap here and there, but sadly a lot of the time the data shows a later prop fitted.
This is what my research has uncovered to date. Not everything is as it should be. (whatever that might be)
Jon