Capt Walter , just now seen your message post
Ya know sometimes there is a slight disappearance around or behind the clouds on some prop textures.
I've experimented with varying degrees of textures too, and Alpha channels to get as close as possible so as not to have that happen, ,, however - it doesn't always work as I'd like !
I've even experimented within the Aircrafts CFG File , in an area called "Prop Animation Ratio", and experimented with changing the Prop Ratio Number settings to either a higher or lower number as to the Effect it'll have on the Spin Prop Ratio , when viewing the propellers from outside the aircraft, and to my amazement fiddling and experimenting with those Prop Animation Ratio settings did somewhat achieve a better Spin Prop Ratio viewing .
Tho NOT all Prop Aircraft have a section in the Aircraft CFG File for Prop Animation Ratio, some do, some don't.
I found that a lotta of the issues are with FS 2004 Prop Aircraft are tied within the Model / Air File itself when trying to convert over to FSX Gold/ Acceleration, some just don't work and appear blurred.
I have scores of Aircraft to SWAP Prop Textures with so eventually after hours upon hours of testing, I'll find a replacement one that works or semi works.
I've edited & repainted a few Spin Prop Textures that worked, just got to be careful with the File, some work best as a BMP other work better as a DDS and some work really great as a 256 color BMP its all trial error until ya get it close as ya can.
Sometimes theres just nothing you can do about it, but get as close as ya can and live with it.

Jetranger