Examples from the 1940s and later by makers such as the House of Hardy are good investments if you find them at bargain prices. So too are modern reels by the better known makers such as Bogdan, Orvis, Pate and others. You can always sell it, or, better yet, trade it and get whatever it is you collect in return. When considering the acquisition of any given reel, you must first examine it for flaws, replaced parts, missing or damaged screws or nuts and, most important, its working order. If the reel is a truly rare one, small flaws can be overlooked, but they cannot be ignored and will adversely affect the overall value.
Flaws can make more common reels virtually worthless.
More collectibles have been ruined by fumble-fingered fools than you can begin to imagine. Don't you be the one to undo what made a reel collectible in the first place. Don't use steel wool on any reel. Don't attempt to straighten bent brass or German silver. Don't try to take a reel apart without using jeweler's tools.