RE: Retiring a Plane
When I'm done with 'em they's used up.
I have given some away, several were rekitted in spectacular fashion, at least two were still flying but were so heavy from repairs and had so many cracked wing ribs that they rattled so I just discontinued the ground maintenance and parted them out. When I get enough of a pile of pieces I have a bonfire and return them the to dust and the whims of air currents. (With a suitable toasting ceremony, of course.)
I can see where a really detailed scale model would deserve a dignified retirement. Ain't nothing I build so lovely that I want to just look at it if it is no longer airworthy.