What constitutes "collectible condition" varies from person to person. To some, anything short of near original condition will be looked at as a "user". You will have to determine for yourself what should be used or left alone. I consider ease of replacement to be a huge factor. For me personally, anything uncommon/rare with an original handle warrants only careful handling and light use. An axe head can take some use and still retain its value but the handles are another story. Original, perfect paper labels means no use to me. If you are just putting a new handle on an older head, I see very little collector value unless you have something very rare which a U.S. marked Collins Legitimus head is not. If you want to use it, buy the head by itself and have a ball. To buy a new old stock original with original handle and paint and then beat it up makes little sense because other examples that are more "broken in" are available for less money. An original US Collins Legitimus axe as issued would be much harder to replace than just a used head.
Some of the "values" of axes right now are misleading, especially with Hudson Bays. Most of them are expensive but not because they are rare or special in any way, they are just currently very popular and people will pay up for them.
Norlunds are bringing crazy prices but they are not rare in any way. The number of listings for them is always high. There are lots to be had in varied conditions. It would not bother me a bit to see someone buy one in near perfect original condition and use it heavily because you could replace it, at least right now, fairly easily because lots are available. If someone bought a new old stock Peavey Hudson Bay and beat the hell out of it, that would make me cry because they are not easy to find in any condition.
If you watch the auctions closely you will realize that there are a lot of lone axe heads that bring almost as much as the same heads on original handles. This always puzzled me as I personally put a high value on the original handles. I think the reason the heads bring those prices is that people want to use their axes and are not really interested in a collectible or a wall hanger. They want a quality head that they can rehandle themselves because they enjoy the "restoration" as a hobby. In addition, they may worry about an old handle being sound or they do not want to worry about ruining a nice old handle.
