No worries.
I used to work in G.A. maintenance for a couple of years, and that's where I also got my own deco-prop.
We had people asking for old propellers and cockpit-instruments quite frequently, and usually had to disappoint them.
As for the part that was misunderstood to be cheeky: I didn't know the extent of your technical knowledge of airplanes. If you (like most people, please don't take it personally) just ask for a "Cherokee-propeller", then the owner of the prop will certainly know what you mean, but he will also be sure that you have no idea about what you're talking about - so he'll happily sell it to you at his price.
Secondly, if you buy one over the internet (which I think you will end up doing), and you're not more specific about what you want, you might well be given a variable-pitch prop from, for example, a DA-20. It's made of wood and therefore worthless for recycling, and good for nothing to you: They look ugly when broken (with bits of plastic dangling off and cracked paint peelings), and unlike the prop from various other planes, where the propeller really is just two, three or four loose single blades that have yet to be attached to an independent module, it consists of the complete gear assembly. That thing is huge and heavy, and you would find it very difficult to fix it to your wall. Later you may also discover that even after a thorough cleaning there will always be oil dripping out of it - nice, if it happens in your living room.
Rhyspiper, I'm not patronizing you at all - why would I?
"Assumption is the mother of all screw-ups"
