I have been thinking if it would be possible, either to:-
Extend the function of the regular spray can to include the skins from /skin
Implement a clone of the spray can you could buy with net worth (RustEZ Spray Can) that would have the extra skins available in it. (and keep the normal can separate)
Mainly as the spray can was meant to save ripping your doors off to change the skin, but there's no other way to reskin them with the extra skins available (/skin) as the regular spray can will only let you use ones from your steam inventory.
Depends if this is reasonable to achieve within the realm of sanity?