I am not sure whether "collecting" is the appropriate word. What I mean is getting something mainly for the sake of having/displaying it, not using it. This question was triggered by a recent rifle question (that looks like a collectible to me, but might not be - no expert there). However I believe there is a broader point here, e.g. knives, old ice axes, ... may be collected. They were used in the outdoors, but the act of collecting those isn't obviously outdoorsy.
Do we want questions about collecting outdoor-related items?
The obvious examples are "How/Where can I obtain XY?", but it might also be something like "How many Xs of type Y do still exist/are still usable?".