Ronster, that was a good shot of the full-size prop 'turbines' you posted back there.
One last observation on this - Remember that 'bottom' portion of the (uppermost) turbine which you originally queried and highlighted with a red outline?
Well, the strange thing is...while it is indeed just a 'thicker' rim portion of the turbine's lower half compared to the thinner rim at the top half, it seems that it's the *opposite* way round in the full-size X-Wing shot you've just shown in your last post - compared to Luke's 'cockpit' prop, the uppermost turbine on the full-size X-Wing prop has the 'thicker' rim portion on the *top* half, instead of the bottom half! Did the blueprints (or the builders) get mixed up a little, I wonder? :)
*Note* - and just to confuse things further, a lot of non-movie X-Wing images inaccurately show the 'circular' rims of the turbines as being the *same* thickness in both the top and bottom halves.