It occurred to me to offer some advice to the OP. I really should have thought of it yesterday.
To Copcrap, I don't know how much experience you have with leaf-spring powered switchblades, so at the very least, for my own peace of mind, I want to offer this friendly advice, just in case you didn't already know-
With a leaf-spring powered switchblade it's important that you avoid repeatedly firing (opening) and closing the knife over and over again. Such activity can over-stress the spring and cause it to break. Leaf-spring switchblades were intended to be opened and closed occasionally, like a regular pocketknife. I know how addictive the action of a switchblade can be, it is something that causes many people to repetitiously fire their knives, which in turn often results in the spring breaking.
But I don't mean to suggest that such switchblades need to be treated gingerly. It shouldn't cause any problems to fire a leaf-spring switchblade 2 or 3 times every hour of the day. The important thing is that the spring receive a certain amount of "rest". I personally prefer not to fire one more than twice in a row, and then after ten minutes or so I might fire it again (to satisfy my craving

), and then that's all for awhile.
It looks like the spring in your knife has a short amount of travel (the distance the blade pushes it back into the handle). This means that there isn't as much stress being inflicted on the spring during closing, which means less chance of breakage, but I still advise everything I mentioned above to keep your knife functional and firing strong for a long time to come. There's no reason why a leaf-spring fired switchblade (like yours) couldn't last the rest of your life, or beyond, as long as it isn't excessively fired.
Again, just some friendly advice. You have quite a find there in that knife, and I would hate for it to suffer a broken spring. There are people who can make new springs by copying the old/broken one, but they don't work cheap.
I wish you and your knife the best, and I hope it brings you joy for as long as you choose to keep it. It truly is something rare, and in my opinion, very special.
